Direct link communications in multi-link operations

ABSTRACT

Certain aspects of the present disclosure provide techniques for handling direct link communications in multi-link systems. An example method generally includes transmitting, to a first wireless station via a direct link between the first wireless station and one or more second wireless stations affiliated with a multi-link device (MLD), a data frame comprising a transmitter address field set to an address of the MLD, which is one of a plurality of addresses associated with the MLD and the second wireless stations being affiliated with the MLD for multi-link operations. The method also includes communicating with the first wireless station via the direct link.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present Application for Patent claims priority to U.S. ProvisionalApplication No. 63/094,684, filed Oct. 21, 2020, which is herebyexpressly incorporated by reference herein in its entirety.

BACKGROUND Field of the Disclosure

Certain aspects of the present disclosure generally relate to wirelesscommunications and, more particularly, various techniques and apparatusfor handling direct link communications in multi-link systems.

Description of Related Art

In order to address the issue of increasing bandwidth requirementsdemanded for wireless communications systems, various schemes are beingdeveloped to allow multiple wireless stations to communicate with asingle access point by sharing the channel resources while achievinghigh data throughputs.

Multiple Input Multiple Output (MIMO) technology represents one suchapproach that has emerged as a popular technique for communicationsystems. MIMO technology has been adopted in several wirelesscommunications standards such as the IEEE 802.11 standard (includingamendments thereto such as 802.11ax, 802.11ay and 802.11be). Certainwireless communications standards, such as the Institute of Electricaland Electronics Engineers (IEEE) 802.11 standard (including amendmentsthereto such as 802.11ax, 802.11ay and 802.11be), denotes a set ofWireless Local Area Network (WLAN) air interface standards developed bythe IEEE 802.11 committee for short-range communications (e.g., tens ofmeters to a few hundred meters).

Some wireless networks, such as 802.11be networks (also referred to asExtremely High Throughput (EHT) networks), enable certain wirelesscommunication devices (which may be referred to as multi-link devices(MLDs)) to communicate via two or more wireless communication linksacross the available bands (2.4, 5, and 6 GHz bands) simultaneously, forexample, using multi-link operation (MLO) and/or multi-link aggregation(MLA).

SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that provide desirablelatencies and/or throughputs due to multi-link operations.

Certain aspects of the present disclosure provide a method of wirelesscommunications by a multi-link device (MLD). The method generallyincludes transmitting, to a first wireless station via a direct linkbetween the first wireless station and one or more second wirelessstations associated with the MLD, a data frame comprising a transmitteraddress field set to an address of the MLD, which is one of a pluralityof addresses associated with the MLD and the second wireless stationsbeing associated with the MLD for multi-link operations. The method alsoincludes communicating with the first wireless station via the directlink.

Certain aspects of the present disclosure provide a method of wirelesscommunications by an MLD. The method generally includes communicatingwith a first wireless station via a direct link between the firstwireless station and a second wireless station, the second wirelessstation being associated with the MLD, wherein the direct link isinoperative for the MLD while a third wireless station associated withthe MLD is communicating. The method further includes receiving, from anaccess point, a request-to-send (RTS) frame requesting to send data tothe third wireless station associated with the MLD, and taking one ormore actions in response to the RTS frame.

Certain aspects of the present disclosure provide a method of wirelesscommunications by an access point. The method generally includesreceiving, from an MLD, a first indication to enable transmission of anRTS frame before a transmission from the access point to the MLD. Themethod further includes transmitting, to the MLD, the RTS framerequesting to send data to one or more wireless stations associated withthe MLD based on the first indication. The method also includestransmitting, to the one or more wireless stations, the data if aclear-to-send (CTS) frame is received by the access point from the MLD.

Certain aspects of the present disclosure provide a method of wirelesscommunications by an MLD. The method generally includes transmitting, toan access point, a first indication that a first wireless stationassociated with the MLD is in power save mode. The method also includescommunicating, after transmission of the first indication, with a secondwireless station via a direct link between the second wireless stationand a third wireless station, the third wireless station beingassociated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

Certain aspects of the present disclosure provide a method of wirelesscommunications by an MLD. The method generally includes transmitting, toan access point, an indication to disable a link to a first wirelessstation associated with the MLD. The method also includes communicating,after the transmission of the indication, with a second wireless stationvia a direct link between the second wireless station and a thirdwireless station, the third wireless station being associated with theMLD, wherein the direct link is inoperative for the MLD while the firstwireless station is communicating.

Certain aspects of the present disclosure provide a method of wirelesscommunications by a first MLD. The method generally includescommunicating, with a second MLD, via a dynamic link set comprising aplurality of links between first access points associated with thesecond MLD and first wireless stations associated with the first MLD.The method further includes transmitting, to one or more of the firstaccess points, a first indication to remove a link in the dynamic linkset between the one or more of the first access points and one or moreof the first wireless stations. The method also includes communicating,after the transmission of the first indication, with a second wirelessstation via a direct link between the second wireless station and athird wireless station associated with the first MLD, wherein the directlink is inoperative for the first MLD while the one or more of the firstwireless stations are communicating.

Certain aspects of the present disclosure provide a method of wirelesscommunications by a first MLD. The method generally includes receiving,from a second MLD via a first access point associated with the firstMLD, one or more first frames related to establishing a direct linkbetween the second MLD and a first wireless station, wherein the firstwireless station does not support multi-link operations. The methodfurther includes relaying, to the first wireless station via the firstaccess point, the one or more first frames, wherein the one or morefirst frames include a source address field set to an address of asecond wireless station associated with the second MLD.

Certain aspects of the present disclosure provide a method of wirelesscommunications by a first wireless station. The method generallyincludes transmitting, to a second wireless station via an access point,a request to discover the second wireless station for direct linkcommunications between the first wireless station and the secondwireless station, wherein the request indicates a link forcommunications between the first wireless station and the secondwireless station. The method also includes communicating directly withthe second wireless station via the link indicated in the request.

Certain aspects of the present disclosure provide a first multi-linkdevice (MLD). The MLD generally includes a memory and a processorcoupled to the memory. The processor and the memory are configured totransmit, to a first wireless station via a direct link between thefirst wireless station and at least one of a plurality of secondwireless stations affiliated with the first MLD, a data frame comprisinga transmitter address field set to an address of the first MLD, which isone of a plurality of addresses associated with the first MLD and thesecond wireless stations being affiliated with the first MLD formulti-link operations, and communicate with the first wireless stationvia the direct link.

Certain aspects of the present disclosure provide a method of wirelesscommunication by a first multi-link device (MLD). The method generallyincludes transmitting, to a first wireless station via a direct linkbetween the first wireless station and at least one of a plurality ofsecond wireless stations affiliated with the first MLD, a data framecomprising a transmitter address field set to an address of the firstMLD, which is one of a plurality of addresses associated with the firstMLD and the second wireless stations being affiliated with the first MLDfor multi-link operations, and communicating with the first wirelessstation via the direct link.

Certain aspects of the present disclosure provide a multi-link device(MLD). The MLD generally includes a memory and a processor coupled tothe memory. The processor and the memory are configured to establish adirect link between a first wireless station and a second wirelessstation affiliated with the MLD; and communicate with the first wirelessstation via the direct link, wherein the direct link is inoperative forthe MLD while a third wireless station affiliated with the MLD iscommunicating.

Certain aspects of the present disclosure provide an access point. Theaccess point generally includes a memory and a processor coupled to thememory. The processor and the memory are configured to receive, from amulti-link device (MLD), an indication of a state associated with theMLD or one or more wireless stations affiliated with the MLD, transmit,to the MLD, a first frame requesting to send data to the one or morewireless stations affiliated with the MLD based on the state, andtransmit, to the one or more wireless stations, the data if a secondframe granting permission to send the data is received by the accesspoint from the MLD.

Certain aspects of the present disclosure provide a multi-link device(MLD). The MLD generally includes a memory and a processor coupled tothe memory. The processor and the memory are configured to transmit, toan access point or an access point (AP) MLD, a first indicationassociated with a first wireless station affiliated with the MLD, andcommunicate, after transmission of the first indication, with a secondwireless station via a direct link between the second wireless stationand a third wireless station, the third wireless station beingaffiliated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

Certain aspects of the present disclosure provide a method of wirelesscommunication by a first multi-link device (MLD). The method generallyincludes establishing a direct link between a first wireless station anda second wireless station affiliated with the MLD; and communicatingwith the first wireless station via the direct link, wherein the directlink is inoperative for the MLD while a third wireless stationaffiliated with the MLD is communicating.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects.

FIG. 1 is a diagram illustrating an example wireless communicationnetwork, in accordance with certain aspects of the present disclosure.

FIG. 2 is a block diagram conceptually illustrating a design of anexample access point (AP) and wireless stations (STAs), in accordancewith certain aspects of the present disclosure.

FIG. 3 is a block diagram illustrating an example of multi-linkoperations between multi-link devices (MLDs), in accordance with certainaspects of the present disclosure.

FIG. 4 is a flow diagram illustrating example operations for wirelesscommunication by an MLD, in accordance with certain aspects of thepresent disclosure.

FIG. 5A is a diagram illustrating an MLD initiating a direct link setupwith a legacy STA and communicating via the direct link with the legacySTA, in accordance with certain aspects of the present disclosure.

FIG. 5B is a diagram illustrating a legacy STA initiating a direct linksetup with an MLD and communicating via the direct link with the MLD, inaccordance with certain aspects of the present disclosure.

FIG. 6 is a diagram illustrating an example link identifier informationelement format, in accordance with certain aspects of the presentdisclosure.

FIG. 7A is a diagram illustrating a first MLD initiating a direct linksetup with a second MLD and communicating via the direct link with thesecond MLD, in accordance with certain aspects of the presentdisclosure.

FIG. 7B is a diagram illustrating the second MLD initiating a directlink setup with the first MLD and communicating via the direct link withthe first MLD, in accordance with certain aspects of the presentdisclosure.

FIG. 8 is a flow diagram illustrating example operations for wirelesscommunication by an MLD (e.g., an AP MLD), in accordance with certainaspects of the present disclosure.

FIG. 9A is a diagram illustrating an AP MLD relaying direct linkmessages from a non-AP MLD to a legacy STA, in accordance with certainaspects of the present disclosure.

FIG. 9B is a diagram illustrating an AP MLD relaying direct linkmessages from a legacy STA to a non-AP MLD, in accordance with certainaspects of the present disclosure.

FIGS. 10A and 10B are flow diagrams illustrating example operations forwireless communication by an MLD (e.g., a non-AP MLD), in accordancewith certain aspects of the present disclosure.

FIG. 11 is a flow diagram illustrating example operations for wirelesscommunication by an MLD (e.g., an AP MLD), in accordance with certainaspects of the present disclosure.

FIG. 12 is a signaling flow diagram illustrating example signaling ofReady-To-Send/Clear-To-Send frames, in accordance with aspects of thepresent disclosure.

FIGS. 13A and 13B are flow diagrams illustrating example operations forwireless communication by an MLD (e.g., a non-AP MLD), in accordancewith certain aspects of the present disclosure.

FIG. 14 is a signaling flow diagram illustrating example signaling ofpower save mode, in accordance with aspects of the present disclosure.

FIG. 15 is a flow diagram illustrating example operations for wirelesscommunication by an MLD (e.g., a non-AP MLD), in accordance with certainaspects of the present disclosure.

FIG. 16 is a flow diagram illustrating example operations for wirelesscommunication by an MLD (e.g., a non-AP MLD), in accordance with certainaspects of the present disclosure.

FIG. 17 is a signaling flow diagram illustrating example signaling ofdisabling/removing a link, in accordance with aspects of the presentdisclosure.

FIG. 18 is a flow diagram illustrating example operations for wirelesscommunication by a wireless station, in accordance with certain aspectsof the present disclosure.

FIG. 19 is a diagram illustrating an example multi-link informationelement format, in accordance with certain aspects of the presentdisclosure.

FIG. 20 is a signaling flow diagram illustrating example signaling ofcross-over of a discovery request, in accordance with aspects of thepresent disclosure.

FIG. 21 illustrates a communications device (e.g., a non-AP MLD orwireless station) that may include various components configured toperform operations for the techniques disclosed herein in accordancewith aspects of the present disclosure.

FIG. 22 illustrates a communications device (e.g., an AP MLD) that mayinclude various components configured to perform operations for thetechniques disclosed herein in accordance with aspects of the presentdisclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processingsystems, and computer readable mediums for handling direct linkcommunications in multi-link operations (MLO).

In certain cases, wireless stations (STAs) may communicate with eachother via a direct wireless link, such as a Tunneled Direct Link Setup(TDLS) link. While establishing the direct link, the STAs may exchangemessages (for example, TDLS frames) through an access point (AP). Whenan AP relays frames on behalf of one associated STA to anotherassociated STA, the AP may set the A3 field (e.g., the source address(SA) field) to the MAC address of the initiator STA. In the case of anon-AP multi-link device (MLD), the AP sets the SA field to the MACaddress of the non-AP MLD. That is, in MLO, the SA field is the MLD MACaddress for a frame relayed by the AP from a non-AP MLD. In TDLS,discovery and setup frames may be sent through the AP while frames sent,after setup is successful and TDLS direct link is established, areexchanged directly between the STAs. The AP may treat TDLS discovery andsetup frames as data without assistance to setup the TDLS between STAs.For frames sent directly between the STAs, the receiver address (RA) ortransmitter address (TA) fields in a frame may be set to the linkaddress (e.g., the MAC address of a STA entity (e.g., the STA entity310, 312) affiliated with an MLD). A STA, which does not support MLO,may not be able to make the association between MLD MAC address and thelink MAC address, resulting in a TDLS link failure. Further, undercertain 802.11 standards (e.g., 802.11be), there may be ambiguity as tothe value of the TA field when a STA of a non-AP MLD sends a TDLSDiscovery Response frame.

Aspects of the present disclosure provide various techniques andapparatus for handling direct link communication in MLO. For example, aSTA of a non-AP MLD, which is participating in a TDLS connection, mayset the TA field to the non-AP MLD's MAC address for frames sentdirectly to a TDLS peer STA. The STA of the non-AP MLD may set the TDLSinitiator STA Address to the non-AP MLD MAC address in a LinkIdentifier—information element (IE)—in TDLS (Discovery/Setup) Requestframes. The STA of the non-AP MLD may set the TDLS Responder STA Addressto the non-AP MLD MAC address in the Link Identifier information element(IE) in TDLS (Discovery/Setup) Response frames sent in response to aTDLS (Discovery/Setup) Request frame received from the TDLS peer STA.The STA of the non-AP MLD may have the ability to process frames withthe RA field set to the MLD MAC. The STA of the non-AP MLD may use theMLD MAC address during the Tunneled Peer Key (TPK) handshake andencryption key generation for the TDLS session. In certain cases, otherSTAs of the non-AP MLD may not be allowed to transmit a frame directedtowards the peer STA with which another STA of the non-AP MLD hasperformed TDLS setup. As used herein, a legacy STA or legacy station mayrefer to a wireless station that does not support MLO or that is notcapable of MLO, such as a wireless station that supports 802.11standards defined before 802.11be.

The various techniques and apparatus for handling direct linkcommunication in MLO may enable direct link communications between anMLD and a legacy STA or another MLD. The direct link communications mayenable desirable latencies and/or throughputs, for example, due to thecommunications without an intermediary device (e.g., an access point).

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any aspect described herein as “exemplary”is not necessarily to be construed as preferred or advantageous overother aspects.

Although particular aspects are described herein, many variations andpermutations of these aspects fall within the scope of the disclosure.Although some benefits and advantages of the preferred aspects arementioned, the scope of the disclosure is not intended to be limited toparticular benefits, uses, or objectives. Rather, aspects of thedisclosure are intended to be broadly applicable to different wirelesstechnologies, system configurations, networks, and transmissionprotocols, some of which are illustrated by way of example in thefigures and in the following description of the preferred aspects. Thedetailed description and drawings are merely illustrative of thedisclosure rather than limiting, the scope of the disclosure beingdefined by the appended claims and equivalents thereof.

The techniques described herein may be used for various broadbandwireless communication systems, including communication systems that arebased on an orthogonal multiplexing scheme. Examples of suchcommunication systems include Spatial Division Multiple Access (SDMA),Time Division Multiple Access (TDMA), Orthogonal Frequency DivisionMultiple Access (OFDMA) systems, Single-Carrier Frequency DivisionMultiple Access (SC-FDMA) systems, and so forth. An SDMA system mayutilize sufficiently different directions to simultaneously transmitdata belonging to multiple user terminals. A TDMA system may allowmultiple user terminals to share the same frequency channel by dividingthe transmission signal into different time slots, each time slot beingassigned to different user terminal. An OFDMA system utilizes orthogonalfrequency division multiplexing (OFDM), which is a modulation techniquethat partitions the overall system bandwidth into multiple orthogonalsub-carriers. These sub-carriers may also be called tones, bins, etc.With OFDM, each sub-carrier may be independently modulated with data. AnSC-FDMA system may utilize interleaved FDMA (IFDMA) to transmit onsub-carriers that are distributed across the system bandwidth, localizedFDMA (LFDMA) to transmit on a block of adjacent sub-carriers, orenhanced FDMA (EFDMA) to transmit on multiple blocks of adjacentsub-carriers. In general, modulation symbols are sent in the frequencydomain with OFDM and in the time domain with SC-FDMA. The techniquesdescribed herein may be utilized in any type of applied to SingleCarrier (SC) and SC-Multiple Input Multiple Output (MIMO) systems.

The teachings herein may be incorporated into (e.g., implemented withinor performed by) a variety of wired or wireless apparatuses (e.g.,nodes). In some aspects, a wireless node implemented in accordance withthe teachings herein may comprise an access point or an access terminal.

An access point (“AP”) may comprise, be implemented as, or known as aNode B, a Radio Network Controller (“RNC”), an evolved Node B (eNB), aBase Station Controller (“BSC”), a Base Transceiver Station (“BTS”), aBase Station (“BS”), a Transceiver Function (“TF”), a Radio Router, aRadio Transceiver, a Basic Service Set (“BSS”), an Extended Service Set(“ESS”), a Radio Base Station (“RBS”), or some other terminology.

An access terminal (“AT”) may comprise, be implemented as, or known as asubscriber station, a subscriber unit, a mobile station, a remotestation, a remote terminal, a user terminal, a user agent, a userdevice, user equipment, a user station, or some other terminology. Insome implementations, an access terminal may comprise a cellulartelephone, a cordless telephone, a Session Initiation Protocol (“SIP”)phone, a wireless local loop (“WLL”) station, a personal digitalassistant (“PDA”), a handheld device having wireless connectioncapability, a Wireless Station (“STA”), or some other suitableprocessing device connected to a wireless modem. Accordingly, one ormore aspects taught herein may be incorporated into a phone (e.g., acellular phone or smart phone), a computer (e.g., a laptop), a portablecommunication device, a portable computing device (e.g., a personal dataassistant), an entertainment device (e.g., a music or video device, or asatellite radio), a global positioning system device, or any othersuitable device that is configured to communicate via a wireless orwired medium. In some aspects, the node is a wireless node. Suchwireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as the Internet or a cellular network)via a wired or wireless communication link.

FIG. 1 is a diagram illustrating an example wireless communicationsystem 100 with access points and wireless stations. As shown in FIG. 1,an access point (AP) 110 includes a link manager 112 that may perform aRTS/CTS exchange and/or setting the SA fields when relaying framesbetween a legacy STA and a non-AP MLD, in accordance with aspects of thepresent disclosure. The wireless station (STA) 120 a includes a linkmanager 122 that sets the TA field to specific address to enable directlink communications between the wireless station 120 a and a legacystation (e.g., the wireless station 120 g) and that takes variousactions to prevent or mitigate a simultaneous transmit-receive (STR)state for specific STA entities, in accordance with aspects of thepresent disclosure. In aspects, the wireless station 120 a may be amulti-link device (MLD) as further described herein with respect to FIG.3.

For simplicity, only one access point 110 is shown in FIG. 1. An accesspoint is generally a fixed station that communicates with the wirelessstations and may also be referred to as a base station or some otherterminology. A wireless station may be fixed or mobile and may also bereferred to as a mobile station, a wireless device or some otherterminology. Access point 110 may communicate with one or more wirelessstations 120 at any given moment on the downlink and uplink. Thedownlink (i.e., forward link) is the communication link from the accesspoint to the wireless stations, and the uplink (i.e., reverse link) isthe communication link from the wireless stations to the access point. Awireless station may also communicate peer-to-peer with another wirelessstation, for example, via direct link such as a tunneled direct linksetup (TDLS). A system controller 130 may be in communication with andprovide coordination and control for the access points.

While portions of the following disclosure will describe wirelessstations 120 capable of communicating via Spatial Division MultipleAccess (SDMA), for certain aspects, the wireless stations 120 may alsoinclude some wireless stations that do not support SDMA. Thus, for suchaspects, an access point (AP) 110 may be configured to communicate withboth SDMA and non-SDMA wireless stations. This approach may convenientlyallow older versions of wireless stations (“legacy” stations) to remaindeployed in an enterprise, extending their useful lifetime, whileallowing newer SDMA wireless stations to be introduced as deemedappropriate.

The system 100 employs multiple transmit and multiple receive antennasfor data transmission on the downlink and uplink. The access point 110is equipped with N_(ap) antennas and represents the multiple-input (MI)for downlink transmissions and the multiple-output (MO) for uplinktransmissions. A set of K selected wireless stations 120 collectivelyrepresents the multiple-output for downlink transmissions and themultiple-input for uplink transmissions. For pure SDMA, it is desired tohave N_(ap)≥K≥1 if the data symbol streams for the K wireless stationsare not multiplexed in code, frequency or time by some means. K may begreater than N_(ap) if the data symbol streams can be multiplexed usingTDMA technique, different code channels with CDMA, disjoint sets ofsubbands with OFDM, and so on. Each selected wireless station transmitsuser-specific data to and/or receives user-specific data from the accesspoint. In general, each selected wireless station may be equipped withone or multiple antennas (i.e., N_(sta)≥1). The K selected wirelessstations can have the same or different number of antennas.

The system 100 may be a time division duplex (TDD) system or a frequencydivision duplex (FDD) system. For a TDD system, the downlink and uplinkshare the same frequency band. For an FDD system, the downlink anduplink use different frequency bands. MIMO system 100 may also utilize asingle carrier or multiple carriers for transmission. Each wirelessstation may be equipped with a single antenna or multiple antennas. Thesystem 100 may also be a TDMA system if the wireless stations 120 sharethe same frequency channel by dividing transmission/reception intodifferent time slots, each time slot being assigned to differentwireless station 120.

FIG. 2 illustrates a block diagram of access point 110 and two wirelessstations 120 m and 120 x in a MIMO/MLO system 100. In certain aspects,the access point 110 and/or the wireless stations 120 m and 120 x mayperform various techniques for handling direct link communicationsbetween wireless stations in MLO systems, for example, as furtherdescribed herein with respect to FIGS. 4-20. For example, the accesspoint 110 and/or the wireless stations 120 m and 120 x may include arespective link manager as described herein with respect to FIG. 1.

The access point 110 is equipped with N_(ap) antennas 224 a through 224t. Wireless station 120 m is equipped with N_(sta,m) antennas 252 mathrough 252 mu, and wireless station 120 x is equipped with N_(sta,x)antennas 252 xa through 252 xu. The access point 110 is a transmittingentity for the downlink and a receiving entity for the uplink. Eachwireless station 120 is a transmitting entity for the uplink and areceiving entity for the downlink. As used herein, a “transmittingentity” is an independently operated apparatus or device capable oftransmitting data via a wireless channel, and a “receiving entity” is anindependently operated apparatus or device capable of receiving data viaa wireless channel. The term communication generally refers totransmitting, receiving, or both. In the following description, thesubscript “DL” denotes the downlink, the subscript “UL” denotes theuplink, N_(UL) wireless stations are selected for simultaneoustransmission on the uplink, N_(DL) wireless stations are selected forsimultaneous transmission on the downlink, N_(UL) may or may not beequal to N_(DL), and N_(UL) and N_(DL) may be static values or canchange for each scheduling interval. The beam-steering or some otherspatial processing technique may be used at the access point andwireless station.

On the uplink, at each wireless station 120 selected for uplinktransmission, a TX data processor 288 receives traffic data from a datasource 286 and control data from a controller 280. TX data processor 288processes (e.g., encodes, interleaves, and modulates) the traffic datafor the wireless station based on the coding and modulation schemesassociated with the rate selected for the wireless station and providesa data symbol stream. A TX spatial processor 290 performs spatialprocessing on the data symbol stream and provides N_(sta,m) transmitsymbol streams for the N_(sta,m) antennas. Each transceiver (TMTR) 254receives and processes (e.g., converts to analog, amplifies, filters,and frequency upconverts) a respective transmit symbol stream togenerate an uplink signal. N_(sta,m) transceivers 254 provide N_(sta,m)uplink signals for transmission from N_(sta,m) antennas 252 to theaccess point.

N_(UL) wireless stations may be scheduled for simultaneous transmissionon the uplink. Each of these wireless stations performs spatialprocessing on its data symbol stream and transmits its set of transmitsymbol streams on the uplink to the access point.

At access point 110, N_(ap) antennas 224 a through 224 ap receive theuplink signals from all N_(UL) wireless stations transmitting on theuplink. Each antenna 224 provides a received signal to a respectivetransceiver (RCVR) 222. Each transceiver 222 performs processingcomplementary to that performed by transceiver 254 and provides areceived symbol stream. An RX spatial processor 240 performs receiverspatial processing on the N_(ap) received symbol streams from N_(ap)transceiver 222 and provides N_(UL) recovered uplink data symbolstreams. The receiver spatial processing is performed in accordance withthe channel correlation matrix inversion (CCMI), minimum mean squareerror (MMSE), soft interference cancellation (SIC), or some othertechnique. Each recovered uplink data symbol stream is an estimate of adata symbol stream transmitted by a respective wireless station. An RXdata processor 242 processes (e.g., demodulates, deinterleaves, anddecodes) each recovered uplink data symbol stream in accordance with therate used for that stream to obtain decoded data. The decoded data foreach wireless station may be provided to a data sink 244 for storageand/or a controller 230 for further processing.

On the downlink, at access point 110, a TX data processor 210 receivestraffic data from a data source 208 for N_(DL) wireless stationsscheduled for downlink transmission, control data from a controller 230,and possibly other data from a scheduler 234. The various types of datamay be sent on different transport channels. TX data processor 210processes (e.g., encodes, interleaves, and modulates) the traffic datafor each wireless station based on the rate selected for that wirelessstation. TX data processor 210 provides N_(DL) downlink data symbolstreams for the N_(DL) wireless stations. A TX spatial processor 220performs spatial processing (such as a precoding or beamforming, asdescribed in the present disclosure) on the N_(DL) downlink data symbolstreams, and provides N_(ap) transmit symbol streams for the N_(ap)antennas. Each transceiver 222 receives and processes a respectivetransmit symbol stream to generate a downlink signal. N_(ap)transceivers 222 providing N_(ap) downlink signals for transmission fromN_(ap) antennas 224 to the wireless stations.

At each wireless station 120, N_(sta,m) antennas 252 receive the N_(ap)downlink signals from access point 110. Each transceiver 254 processes areceived signal from an associated antenna 252 and provides a receivedsymbol stream. An RX spatial processor 260 performs receiver spatialprocessing on N_(sta,m) received symbol streams from N_(sta,m)transceiver 254 and provides a recovered downlink data symbol stream forthe wireless station. The receiver spatial processing is performed inaccordance with the CCMI, MMSE or some other technique. An RX dataprocessor 270 processes (e.g., demodulates, deinterleaves and decodes)the recovered downlink data symbol stream to obtain decoded data for thewireless station.

At each wireless station 120, a channel estimator 278 estimates thedownlink channel response and provides downlink channel estimates, whichmay include channel gain estimates, SNR estimates, noise variance and soon. Similarly, a channel estimator 228 estimates the uplink channelresponse and provides uplink channel estimates. Controller 280 for eachwireless station typically derives the spatial filter matrix for thewireless station based on the downlink channel response matrix H_(dn,m)for that wireless station. Controller 230 derives the spatial filtermatrix for the access point based on the effective uplink channelresponse matrix H_(up,eff). Controller 280 for each wireless station maysend feedback information (e.g., the downlink and/or uplinkeigenvectors, eigenvalues, SNR estimates, and so on) to the accesspoint. Controllers 230 and 280 also control the operation of variousprocessing units at access point 110 and wireless station 120,respectively.

In certain wireless communication networks (e.g., 802.11be networks), amulti-link device (MLD) may be a wireless communication device withmultiple affiliated APs or STAs. The MLD may have a single medium accesscontrol (MAC) service access point (SAP) to a logical link control (LLC)layer. The MLD may also have a MAC address that uniquely identifies theMLD management entity. An MLD may support various multi-link operations(MLO). In aspects, MLO may include multi-band aggregation, where two ormore channels at different bands (e.g., 2.4, 5, and 6 GHz bands) arecombined to achieve higher transmission rates. In aspects, the 6 GHzband may include a frequency range of 5.925-7.125 GHz. For example, asingle frame may be split and transmitted simultaneously through thedifferent channels at the different bands, reducing the framestransmission time or facilitating transmission of larger aggregatedframes. MLO may include multi-band and multi-channel full duplexcommunications, which is achieved through transmitting and receiving ondifferent channels (in the same or different bands) at the same time.MLO may include data and control plane separation on to differentchannels (in the same or different bands). In certain aspects, MLO maybe implemented with a multi-link single radio (MLSR) architecture, wherethe multiple affiliated APs or STAs of an MLD may be logical devicesunder a single radio.

FIG. 3 is a block diagram illustrating example multi-link operationsbetween MLDs, in accordance with certain aspects of the presentdisclosure. As shown, an AP MLD 302 may communicate with a non-AP MLD304 via multi-link communications, such as multi-band aggregation. TheAP MLD 302 may also be in communication with other systems (e.g., adistribution system (DS) such as a local area network and/or a wide areanetwork) via an interface 318, such as a backhaul interface. The AP MLD302 may include at least two STA entities 306, 308 (sometimes referredto as STA instances and also referred to herein simply as STAs) that maycommunicate with associated STA entities 310, 312 of the non-AP MLD 304.A STA entity (or instance) of an AP MLD are generally APs (which may bereferred to as AP-STAs or STAs serving as APs), and a STA entity of anon-AP MLD are generally non-AP STAs (which may be referred to simply asa STA). MLDs may use multi-link operations, such as multi-linkaggregation (MLA) (which includes packet level aggregation), where MACprotocol data units (MPDUs) from a same traffic ID (TID) can be sent viatwo or more links 314, 316.

In aspects, each of the STA entities 306, 308 may communicate onseparate bands (e.g., 2.4, 5, and 6 GHz bands), and similarly, each ofthe STA entities 310, 312 may communicate on separate bands (2.4, 5, and6 GHz bands). For example, the STA entities 306, 310 may communicatewith each other on a first link 314 via a first band (e.g., 5 GHz band),and the STA entities 308, 312 may communicate with each other on asecond link 316 via a second band (e.g., 6 GHz band). The aggregatedlinks 314, 316 may enable desirable throughputs and latencies betweenthe AP MLD 302 and the non-AP MLD 304. In aspects, the STA entities(306, 308 or 310, 312) of an MLD may be implemented as separate devicesor RF transceiver chips of the MLD, or the STA entities may beintegrated into the same device or RF transceiver chip. In certainaspects, a link may refer to a physical path having one traversal of thewireless medium (WM) that is usable to transfer various packets,messages, or frames (such as MAC service data units (MSDUs)) between twostations (STAs).

Example Direct Link Communications in Multi-Link Operations

In certain cases, STAs may communicate with each other via a directwireless link, such as a Tunneled Direct Link Setup (TDLS) link. Whileestablishing the direct link, the STAs may exchange messages (forexample, TDLS frames) through an AP. When an AP relays frames on behalfof one associated STA to another associated STA, the AP may set the A3field (e.g., the source address (SA) field) to the MAC address of theinitiator STA. In the case of a non-AP MLD, the AP sets the SA field tothe MAC address of the non-AP MLD. That is, in MLO, the SA field is theMLD MAC address for a frame relayed by the AP from a non-AP MLD. InTDLS, discovery and setup frames may be sent thru the AP while framessent after setup are exchanged directly between the STAs. For framessent directly between the STAs, the receiver address (RA) or transmitteraddress (TA) fields in a frame may be set to the link address (e.g., theMAC address of a STA entity (e.g., the STA entity 310, 312) affiliatedwith an MLD). A STA, which does not support MLO, may not be able to makethe association between MLD MAC address and the link MAC address,resulting in a TDLS link failure. Further, under certain 802.11standards (e.g., 802.11be), there may be ambiguity as to the value ofthe TA field when a STA of a non-AP MLD sends a TDLS Discovery Responseframe.

Aspects of the present disclosure provide various techniques andapparatus for handling direct link communication in MLO. For example, aSTA of a non-AP MLD, which is participating in a TDLS connection, mayset the TA field to the non-AP MLD's MAC address for frames sentdirectly to a TDLS peer STA. The STA of the non-AP MLD may set the TDLSinitiator STA Address to the non-AP MLD MAC address in a LinkIdentifier—information element (IE)—in TDLS (Discovery/Setup) Requestframes. The STA of the non-AP MLD may set the TDLS Responder STA Addressto the non-AP MLD MAC address in the Link Identifier information element(IE) in TDLS (Discovery/Setup) Response frames sent in response to aTDLS (Discovery/Setup) Request frame received from the TDLS peer STA.The STA of the non-AP MLD may have the ability to process frames withthe RA field set to the MLD MAC. The STA of the non-AP MLD may use theMLD MAC address during the Tunneled Peer Key (TPK) handshake andencryption key generation for the TDLS session. In certain cases, otherSTAs of the non-AP MLD may not be allowed to transmit a frame directedtowards the peer STA with which another STA of the non-AP MLD hasperformed TDLS setup. The various techniques and apparatus for handlingdirect link communication in MLO may enable direct link communicationsbetween an MLD and a STA, which does not support MLO.

FIG. 4 illustrates example operations 400 of wireless communications, inaccordance with certain aspects of the present disclosure. Theoperations 400 may be performed, for example, by an MLD (e.g., the STA120 a or the non-AP MLD 304). The operations 400 may be implemented assoftware components that are executed and run on one or more processors(e.g., controller 280 of FIG. 2). In certain aspects, the transmissionand/or reception of signals by the MLD may be implemented via a businterface of one or more processors (e.g., controller 280) that obtainsand/or outputs signals. Further, the transmission and reception ofsignals by the MLD may be enabled, for example, by one or more antennasand/or transceivers (e.g., antenna(s) 252 or transceiver(s) 254 of FIG.2).

The operations 400 may begin at 402, where a first MLD performs TDLSsetup with a first wireless station (e.g., the STA 120 g), for example,as further described herein with respect to FIGS. 5A and 5B. At 404, thefirst MLD may transmit, to the first wireless station via a direct linkbetween the first wireless station and at least one of a plurality ofsecond wireless stations (e.g., the STA 310, 312) associated with (e.g.,affiliated with) the first MLD, a data frame comprising a transmitteraddress (TS) field set to an address of the first MLD, which is one of aplurality of addresses associated with the first MLD, and the secondwireless stations being associated with (affiliated with) the first MLDfor MLO. At 406, the first MLD may communicate with the wireless stationvia the direct link. As used herein, a wireless station associated withan MLD may refer to a wireless station affiliated with the MLD.

In certain aspects, the transmission at 404 may be a transmission sentdirectly to a TDLS peer STA (e.g., the first wireless station) withoutan AP relaying the data frame to the TDLS peer STA. At 404, the firstMLD may have a TDLS link established with the first wireless station,and the transmission at 404 may be via the TDLS link. In other words,the direct link may include a tunneled direct link such as a TDLS link.In aspects, the first MLD may communicate with the TDLS peer STA via oneor more of the STA entities (e.g., the STA entities 310, 312) on thedirect link. For example, the first MLD may communicate with the TDLSpeer STA via the second wireless station(s), which may be affiliatedwith the first MLD. In aspects, the address of the first MLD may includea MAC address, such as a multi-link logical MAC address. The multi-linklogical MAC address of the first MLD may be a MAC address that uniquelyidentifies the MLD entity (e.g., the MLD 302), which manages the STAentities (e.g., the STA entities 310, 312). In aspects, the multi-linklogical MAC address of the first MLD may be referred to as an MLD MACaddress, which may be a non-AP MLD MAC address. The MLD MAC address maybe a globally unique MAC address or a MAC address that is the same asone of the per-link MAC addresses (e.g., per-STA or per-AP of the MLD).In other words, the TA field at 404 may be set to the multi-link logicalMAC address of the first MLD. The plurality of addresses associated withthe first MLD may include the multi-link logical MAC address and MACaddresses associated with (each of) the second wireless stations (e.g.,the STA entities 310, 312), where the second wireless stations areaffiliated with the first MLD for multi-link operations. For example,the second wireless stations may enable the first MLD to communicatewith another MLD (e.g., the AP MLD 302) via separate bands (e.g., 5 and6 GHz bands) simultaneously.

In certain aspects, the first MLD may set the initiator or responderaddress in a link identifier element of specific TDLS frames (e.g., TDLSdiscovery or setup frames) to the MLD MAC address. An example linkidentifier IE format is further described herein with respect to FIG. 6.At 402, performing TDLS setup may include the first MLD exchanging TDLSdiscovery or setup frames with the first wireless station, for example,as further described herein with respect to FIGS. 5A and 5B.

In aspects, the initiator address of the link identifier IE may be setto the MLD MAC address in TDLS request frames (such as a TDLS DiscoveryRequest frame and/or a TDLS Setup Request frame from a TDLS initiatorstation). For certain aspects, a request, request frame, or initiatorframe associated with the direct link (e.g., TDLS) may include a TDLSDiscovery Request frame and/or a TDLS Setup Request frame. For example,the first MLD may transmit (at 402), to the first wireless station viaan access point (e.g., the AP 110 or AP MLD 302), a request to discovera peer wireless station (such as the first wireless station) for thedirect link. In other words, the first MLD may transmit the request tothe AP, which relays the request to the first wireless station. Therequest may include a link identifier element having a direct linkinitiator address (e.g., a TDLS initiator STA address) set as theaddress of the first MLD (e.g., the MLD MAC address). In aspects, therequest may include a TDLS Discovery Request frame in accordance withthe 802.11 standards. As an example, the first MLD may transmit (at402), to the first wireless station via the access point, a request tosetup the direct link, and the request may include a link identifierelement having a direct link initiator address set as the address of thefirst MLD (e.g., the MLD MAC address). In aspects, the request mayinclude a TDLS Setup Request frame in accordance with the 802.11standards.

In aspects, the responder address of the link identifier IE may be setto the MLD MAC address in TDLS response frames (such as a TDLS DiscoveryResponse frame and/or a TDLS Setup Response frame from a TDLS responderstation). For certain aspects, a response, response frame, or responderframe associated with the direct link may include a TDLS DiscoveryResponse frame and/or a TDLS Setup Response frame. For example, thefirst MLD may transmit, to the first wireless station (at 402), aresponse responsive to a request to discover a peer wireless station(such as the first MLD) for the direct link, and the response mayinclude a link identifier element having a direct link responder addressset as the address of the first MLD (e.g., the MLD MAC address). Inaspects, the first MLD may transmit the response directly to the firstwireless station. The response may include a TDLS Discovery Responseframe in accordance with the 802.11 standards. As an example, the firstMLD may transmit, to the first wireless station via an access point (at402), a response responsive to a request to setup the direct link, andthe response may include a link identifier element having a direct linkresponder address set as the address of the first MLD (e.g., the MLD MACaddress). The response may include a TDLS Setup Request frame inaccordance with the 802.11 standards.

In certain aspects, the first MLD may set the TA field to the MLD MACaddress for a discovery response sent to the first wireless station.Performing TDLS setup at 402 may involve the first wireless stationinitiating discovery of a peer wireless station (such as the first MLD),for example, where the first wireless station sends a TDLS DiscoveryRequest frame to the first MLD via an AP. In such a case, the first MLDmay respond to the TDLS Discovery Request frame with a TDLS DiscoveryResponse frame, which is sent directly to the first wireless station.The first MLD may set the TA field to the MLD MAC address in the TDLSDiscovery Response frame. For example, the first MLD may receive, fromthe first wireless station via an access point, a request to discover apeer wireless station (such as the first MLD) for the direct link. Inaspects, the request may include a TDLS Discovery Request frame. Thefirst MLD may transmit, to the first wireless station (at 402), adiscovery response comprising the TA field set to the address of thefirst MLD (e.g., the MLD MAC address), where the transmission of thediscovery response may be responsive to the request.

At 406, the first MLD may support receiving frames directly from theTDLS peer STA with a receiver address (RA) field set to the MLD MACaddress. For example, at 406, the communication with the first wirelessstation via the direct link may include the first MLD receiving, fromthe first wireless station via the direct link, a frame comprising areceiver address field set to the address of the first MLD (e.g., theMLD MAC address).

In certain aspects, a header of a frame may include the TA/RA fields asdescribed herein. For example, a MAC header of a data frame or TDLSframe may include the TA/RA fields. With respect to the operations 400,the data frame may include a MAC header including the TA field, and thedata frames received at 406 may include a MAC header including the RAfield.

In aspects, a STA entity of the first MLD may use the MLD MAC addressduring the TPK handshake (such as a 4-way handshake) and encryption keygeneration for the TDLS session. For example, the first MLD may generatea security key for the TDLS session using the MLD MAC address. At 402,the first MLD may generate the encryption key based at least in part onthe address of the first MLD and transmit, to the first wirelessstation, an indication of the encryption key (e.g., a parameter used togenerate the encryption key at the first wireless station). For certainaspects, encryption key generation may be further based on an AP MLD MACaddress and/or an AP MAC address. In certain cases, when both wirelessstations, involved in TDLS setup, include the TDLS variant Multi-Linkelement, carrying the AP MLD MAC Address field, in the frames exchangedduring TDLS setup phase, the TDLS TPK generation may include the AP MLDMAC address in addition to the MAC address of the affiliated AP wherethe TDLS direct link is being established. The AP MLD MAC address may beused to generate the encryption key when the MLDs in the TDLS are non-APMLDs for a single link or multi-link TDLS between the MLDs. Thecommunications with the first wireless station at 406 may include thefirst MLD communicating encrypted frames with the first wireless stationbased on the encryption key.

In certain aspects, other STA entities of the first MLD may not beallowed to transmit a frame directed towards the TDLS peer STA. Forexample, one of the second wireless stations (e.g., the STA 310) of thefirst MLD may communicate with the TDLS peer STA via the direct link,and the other second wireless stations (e.g., the STA 312) of the firstMLD may transmit frames to an access point without directing the framesto the TDLS peer STA. After a TDLS direct link is successfullyestablished between the TDLS STA affiliated with a non-AP MLD and a TDLSpeer STA at the other end of the TDLS direct link, STAs affiliated withthe non-AP MLD may cease transmitting packets to the TDLS peer, at theother end, through their associated AP that is affiliated with the APMLD to which the non-AP MLD has performed multi-link setup. In certaincases, the first MLD may cease transmission to the first wirelessstation via the second wireless stations, except for one of the secondwireless stations associated with the direct link, based on the directlink being operative.

In aspects, the access point, which assists in relaying TDLS Discoveryand Setup frames, may be an MLD. For example, at 402, the first MLD mayexchange TDLS Discovery and Setup frames with an access point that is anMLD (e.g., the AP MLD 302).

FIG. 5A is a diagram illustrating an MLD (MLD_S) initiating a TDLS setupwith a legacy STA (STA_3) and communicating via the TDLS link with thelegacy STA, in accordance with certain aspects of the presentdisclosure. As shown, STA1 of the MLD_S may transmit, to AP1 of theMLD_A, a TDLS Discovery Request frame with the TA field set to the STA_1MAC address. The AP1 relays, to the STA_3, the TDLS Discovery Requestframe with the SA field set to the MLD_S MAC address (e.g., the MACaddress of the MLD entity). From the STA_3 perspective, the STA_3 is notaware of the STA entities (STA_1 and STA_2) of the MLD_S. As such, theSTA_3 transmits directly, to the STA_1 of the MLD_S, a TDLS DiscoveryResponse frame with the RA field set to the MLD_S MAC address. The STA_1of the MLD_S may support receiving a frame with the RA field set to theMLD_S MAC address.

The STA_1 of the MLD_S may transmit, to the AP1, a TDLS Setup Requestframe with the TA field set to the STA_1 MAC address, and the AP1 mayrelay, to the STA_3, the TDLS Setup Request frame with the SA field setto the MLD_S MAC address. The STA_3 may transmit, to the AP1, a TDLSSetup Response frame with the destination address (DA) field set to theMLD_S MAC address, and the AP1 may relay, to the STA_1 of the MLD_S, theTDLS Setup Response frame with the RA field set to the STA_1 MACaddress. Upon completion of the TDLS process, the STA_1 of the MLD_S andthe STA_3 may communicate with each other via a TDLS link. The STA_1 ofthe MLD_S may transmit directly, to the STA_3, a data frame with a TAfield set to the MLD_S MAC address, which will enable the STA_3 toreceive the data frame and communicate with the STA_1 due to the STA_3not knowing about the STA_1 MAC address. The STA_3 may transmitdirectly, to the STA_1 of the MLD_S, a data frame with the RA field setto the MLD_S MAC address. As previously described, the STA_1 of theMLD_S may support receiving a frame with the RA field set to the MLD_SMAC address, which enables the STA_1 of the MLD_S to receive TDLS dataframes from the STA_3 due to the STA_3 not knowing about the STA_1 MACaddress.

FIG. 5B is a diagram illustrating a legacy STA (STA_3) initiating a TDLSsetup with an MLD (MLD_S) and communicating via the TDLS link with theMLD, in accordance with certain aspects of the present disclosure. Asshown, the signaling exchange between the STA_3 and MLD_S follows asimilar signaling flow as described herein with respect to FIG. 5A. Forexample, the TDLS frame(s) relayed from the AP1 to the STA_3 have the SAfield set to the MLD_S MAC address, and the TDLS frame(s) relayed fromthe AP1 to the STA_1 have the RA field set to the STA_1 MAC address. Inthis example, the STA1 of the MLD_S transmits directly, to the STA_3, aTDLS Discover Response frame with the TA field set to the MLD_S MACaddress, which will enable the STA_3 to communicate with the STA_1 dueto the STA_3 not knowing about the STA_1 MAC address. After completionof the TDLS process, the STA_1 and STA_3 may transmit data frames withthe RA/TA fields set as described herein with respect to FIG. 5A.

FIG. 6 is a diagram illustrating an example link identifier IE format,in accordance with certain aspects of the present disclosure. As shown,the link identifier IE format may have an element identifier (ID) field(which identifies the element as a link identifier), a length field, abasic service set identifier (BSSID) field, a TDLS initiator STA addressfield, and a TDLS responder STA address field. The initiator STA may bethe STA that sends a TDLS Discovery/Setup Request frame, and theresponder STA may be the STA requested to respond (or responding) to theTDLS Discovery/Setup Request frame. As described herein with respect tothe operations 400, the first MLD may set the TDLS initiator STA addressfield to the MLD MAC address for TDLS request frames (e.g., the TDLSDiscovery/Setup Request frames), and the first MLD may set the TDLSresponder STA address field to the MLD MAC address for the TDLS responseframes (e.g., the TDLS Discovery/Setup Response frames).

Aspects of the present disclosure provide various techniques forhandling direct link communications between MLDs. In certain cases, theMLDs may setup and communicate with each other via separate TDLSsessions on multiple links via multiple STA entities. That is, aseparate TDLS session may be established for each STA entity pairbetween TDLS MLO STA peers. In certain aspects, the MLDs may setup andcommunicate with each other via a single TDLS session on multiple linksvia multiple STA entities. That is, a single TDLS session may beestablished between TDLS MLO STA peers, and the TDLS MLO STA peers maycommunicate with each other via multiple STA entities at each TDLS peer.A single TDLS session may enable a common block acknowledgement sessionwhere packets can be sent on any of the links between STA entities,which may help with duplicate detection. To setup one or more multi-linkTDLS sessions, multi-link support or a request for multi-link TDLS maybe indicated by a BSSID field in Link Identifier element set to awildcard value or a specific value, by including a multi-link elementduring the TDLS Discovery and/or Setup exchange, by identifying the linkassociated with a STA entity via a Link identifier (ID) field in per-STAProfile subfield, by providing provide an MLD's multi-link capabilitiesand/or constraints (such as n-STR links/STAs) for each link associatedwith a STA entity. The MLDs may coordinate transmissions on n-STR linksthat are part of a TDLS session.

The various techniques for handling direct link communication betweenMLDs may enable direct link communications with desirable latencies anddata throughputs, for example, due to the multi-band aggregation and/orother features of MLO.

In certain aspects, the TDLS peer STA of the direct link in theoperations 400 may also be part of an MLD. For example, the firstwireless station may be associated with a second MLD for multi-linkcommunications with the first MLD, and the second MLD further has two ormore third wireless stations being associated therewith for multi-linkcommunications with the first MLD.

With respect to the operations 400, the direct link may include aplurality of tunneled direct link sessions, and each of the plurality oftunneled direct link sessions is associated with a separate link betweenone of the second wireless stations and one of the third wirelessstations. In certain aspects, the direct link may include a singletunneled direct link session, and the plurality of links between thesecond wireless stations and the third wireless stations are associatedwith the single tunneled direct link session.

In certain aspects, the first MLD may indicate to setup a direct linkwith multi-link capabilities (such as MLO/MLA capabilities). In aspects,the first MLD may transmit the indication to setup a direct link withmulti-link capabilities to a legacy STA or another MLD. For example, thefirst MLD may transmit, to the first wireless station, an indication tosetup the direct link as a multi-link direct link. The communicationwith the first wireless station via the direct link at 406 may includethe first MLD communicating with the first wireless station via one ormore links of the multi-link direct link based on the indication. Theindication may include at least one of a BSSID field including a valueindicating to setup the direct link as the multi-link direct link or amulti-link element in a direct link discovery frame or a direct linksetup frame. An example multi-link IE format is further described hereinwith respect to FIG. 19. The value may be set to a link identifierassociated with the link(s). The multi-link element may include a firstindication having an identifier of the direct link in a station profilesub-element associated with at least one of the second wirelessstations, or a second indication of one or more capabilities of thesecond wireless stations associated with links between the secondwireless stations and the third wireless stations. As an example, thecapabilities may indicate whether the wireless stations are STR orn-STR. Capability information may include as one or more fields in theper-STA profile sub-element.

FIG. 7A is a diagram illustrating MLD_S initiating a TDLS setup withMLD_R and communicating via the TDLS link with MLD_R, in accordance withcertain aspects of the present disclosure. As shown, the signalingexchange between the MLD_R and MLD_S follows a similar signaling flow asdescribed herein with respect to FIG. 5A. In certain aspects, the RA,TA, SA, DA fields may be set to the respective MLD MAC addresses (e.g.,the MLD_S MAC address or the MLD_R MAC address). For example, afterestablishing one or more TDLS links, the MLD_S may transmit directly, tothe MLD_R, a data frame with the RA field set to the MLD_R MAC addressand with the TA field set to the MLD_S MAC address. In aspects, the TDLSDiscovery Response frame may also use the MLD MAC addresses. Forexample, the MLD_R may transmit directly, to the MLD_S, the TDLSDiscovery Response frame with the RA field set to the MLD_S MAC addressand with the TA field set to the MLD_R MAC address.

FIG. 7B is a diagram illustrating MLD_R initiating a TDLS setup withMLD_S and communicating via the TDLS link with MLD_S, in accordance withcertain aspects of the present disclosure. As shown, the signalingexchange between the MLD_R and MLD_S follows a similar signaling flow asdescribed herein with respect to FIG. 5A. In certain aspects, the RA,TA, SA, DA fields may be set to the respective MLD MAC addresses (e.g.,the MLD_S MAC address or the MLD_R MAC address), for example, asdescribed herein with respect to FIG. 7A.

Certain aspects of the present disclosure provide techniques forenabling the AP to map the addresses of a non-AP MLD when relayingmessages between a legacy STA and a non-AP MLD. For example, when an APof an AP MLD relays a frame initiated by any STA of a non-AP MLD to alegacy non-AP STA on a particular link, the AP may set the SA field tothe MAC address of the non-AP STA, which is affiliated with the non-APMLD, on that link, instead of the MAC address of the non-AP MLD. The MACaddress of the STA affiliated with the non-AP MLD may enable the legacySTA to communicate with the non-AP MLD via a direct link. Advantages ofcertain aspects may be that the client-side (e.g., non-AP wirelessstations) do not require any changes, such that the multi-link TDLSexchange is handled at the AP to facilitate mapping the correct MACaddress (e.g., the MAC address of a STA affiliated with non-AP MLD) to alegacy STA.

FIG. 8 illustrates example operations 800 of wireless communications, inaccordance with certain aspects of the present disclosure. Theoperations 800 may be performed, for example, by an MLD (e.g., the APMLD 302). The operations 800 may be implemented as software componentsthat are executed and run on one or more processors (e.g., controller230 of FIG. 2). In certain aspects, the transmission and/or reception ofsignals by the MLD may be implemented via a bus interface of one or moreprocessors (e.g., controller 230) that obtains and/or outputs signals.Further, the transmission and reception of signals by the MLD may beenabled, for example, by one or more antennas and/or transceivers (e.g.,antenna(s) 224 or transceiver(s) 222 of FIG. 2).

The operations 800 may begin at 802, where a first MLD (e.g., the AP MLD302 in FIG. 3 or MLD_A in FIGS. 5A and 5B) receives, from a second MLD(e.g., the non-AP MLD 304 in FIG. 3 or MLD_S in FIGS. 5A and 5B) via afirst access point (e.g., the AP 306) associated with the first MLD, oneor more first frames related to establishing a direct link between thesecond MLD and a first wireless station (e.g., STA3 in FIGS. 5A and 5B),where the first wireless station does not support multi-link operations.At 804, the first MLD may relay, to the first wireless station via thefirst access point, the one or more first frames, where the first framesinclude a source address (SA) field set to an address of a secondwireless station associated with the second MLD. At 806, the first MLDmay receive, from the first wireless station via the access point, oneor more second frames related to the establishment of the direct link.At 808, the first MLD may relay, to the second MLD, the second frames,where the second frames include a destination address (DA) field set tothe address of the second wireless station.

In aspects, frames related to establishing a direct link may includeTDLS Discovery/Setup frames. For example, the first MLD may receive aTDLS Discovery Request frame and/or a TDLS Setup Request/Response frameas the first frames. The first MLD may receive a TDLS Discovery Requestframe and/or a TDLS Setup Request/Response frame as the third frames. At804 and 808, the first MLD may relay the first frames and/or the secondframes to the first wireless station or the second MLD. In other words,the relayed frames may be copies or duplicates of the received frameswith changes to the MAC header fields, such as the RA field and/or theSA field.

In aspects, the first MLD may map the address of the second MLD (e.g.,the MLD MAC address of the second MLD) or addresses of the STA entitiesof the second MLD to the address of the second wireless station based onthe first wireless station not supporting MLO, for example, as describedherein with respect to FIGS. 9A and 9B. For example, the first framesmay include a TA field set to the address of the second wirelessstation. As the first MLD may default to setting to the SA field to theMLD MAC address when relaying frames between wireless stations, thefirst MLD may identify that the second MLD supports MLO, while the firstwireless station does not support MLO, and in such a case, the first MLDmay relay the frames with the SA field set to the address of the secondwireless station instead of the address of the second MLD based on themapping between the address of the second MLD and the address of thesecond wireless station.

In certain aspects, the address of the second wireless station may be aMAC address of the second wireless station. The MAC address of thesecond wireless station may be a separate address from the address ofthe second MLD, such as the MLD MAC address of the second MLD, or theMAC address of the second wireless station may be the same as the MACaddress of the second MLD.

FIG. 9A is a diagram illustrating an AP MLD (MLD_A) relaying TDLSmessages from a non-AP MLD (MLD_S) to a legacy STA (STA_3), inaccordance with certain aspects of the present disclosure. As shown, theMLD_A may receive frame(s) from the STA entities (e.g., STA_1 and/orSTA_2) of the MLD_S, where the TA field is set to the respective MACaddress of the STA entity. The MLD_A may relay these frames to theSTA_3, where instead of using the MLD MAC address as the SA field, theMLD_A transmit the relayed frames with the SA field set to the STA_1 MACaddress. With the SA field set to the STA_1 MAC address, the STA_3 maybe able to directly communicate with the STA_1 without the MLD MACaddress of the MLD_S.

FIG. 9B is a diagram illustrating an AP MLD (MLD_A) relaying TDLSmessages from a legacy STA (STA_3) to a non-AP MLD (MLD_S), inaccordance with certain aspects of the present disclosure. As shown, theMLD_A may receive frame(s) from the STA_3, where the DA field is set toMAC address of one of the STA entities of the MLD_S. The MLD_A may relaythese frames to the STA_1 or STA_2 with the RA field set to the MACaddress of the STA_1 or STA_2.

In certain cases, a non-AP MLD may not support simultaneous transmit andreceive (SRT) via two or more of the STA entities. Such a STA of an MLDmay be referred to as a non-SRT (n-SRT) STA or link. That is, the non-APMLD may not be able to simultaneously transmit and receive on two ormore links in separate bands (e.g., 5 and 6 GHz bands). For example, thenon-AP MLD 304 may not support simultaneous transmission via the STA 310while the STA 312 is receiving data from the AP MLD 302, or vice versa(e.g., the STA 310 cannot receive while the STA 312 transmits). Thenon-AP MLD may be able to transmit simultaneously (Tx/Tx) via the STAentities or receive simultaneously (Rx/Rx) via the STA entities onseparate bands (e.g., 5 and 6 GHz bands). In cases where the non-AP MLDhas established a TDLS on one of the n-STR link, the non-AP MLD mayencounter interference an STR state arises on an n-STR links. Forexample, the non-AP MLD may encounter undesirable interference when anAP of an AP MLD transmits downlink data to the non-AP MLD on a link,which is n-STR to a TDLS link of the non-AP MLD, when the TDLS link isbusy.

Aspects of the present disclosure provide various techniques to preventor mitigate an STR state between n-STR links of an MLD. In aspects, thevarious techniques to prevent or mitigate an STR state between n-STRlinks of an MLD may be specific to one or more links between one or moreSTA entities and one or more AP entities in a multi-link context (i.e.,MLO/MLA). The non-AP MLD may indicate to temporarily stop communicationsbetween a STA entity and an AP entity on a link that is n-STR with theTDLS link. In certain aspects, a transmission on a TDLS link may beconsidered a factor in causing deafness on other links of the non-APMLD. Various deaf recovery rules may apply to reception of a frame froma peer TDLS STA. In certain cases, DL transmissions may be allowed onthe TDLS link and any other link(s) of the non-AP MLD with which theTDLS link is STR. The various techniques to prevent or mitigate an STRstate may enable communications at an MLD with desirable latencies anddata throughputs due to desirable signal qualities achieved whilepreventing or mitigating an STR state.

In certain aspects, the AP and non-AP MLD may exchange Request-to-Send(RTS) and Clear-to-Send (CTS) frames before any DL transmission on thelink(s), which are n-STR with the TDLS link, to prevent or mitigate anSTR state. For example, an AP MLD may have two or more APs operating onseparate channels/bands (e.g., in the 5 GHz band and 6 GHz band). TheSTAs (e.g., STA1 and STA2) of a non-AP MLD may form a link with each ofthe APs affiliated with the AP MLD. When STA1 of the non-AP MLD forms aTDLS connection on a first link with another wireless station, thenon-AP MLD may send a request to the AP MLD that when AP MLD transmits aframe to STA2 affiliated with the non-AP MLD on a second link, the AP isto send an RTS on the second link and send the DL frame only if the APMLD receives a CTS response from the non-AP MLD.

FIG. 10A illustrates example operations 1000A of wirelesscommunications, in accordance with certain aspects of the presentdisclosure. The operations 1000A may be performed, for example, by anMLD (e.g., the non-AP MLD 304).

The operations 1000A may begin at 1002, where the MLD may communicatewith a first wireless station (e.g., STA 120 g in FIG. 1, STA_3 in FIGS.5A and 5B, or MLD_R in FIGS. 7A and 7B) via a direct link between thefirst wireless station and a second wireless station (e.g., the STA310), the second wireless station being associated with the MLD, wherethe direct link is inoperative for the MLD while a third wirelessstation (e.g., the STA 312) associated with the MLD is communicating, oranother link associated with the third wireless station is inoperative,while the second wireless station is communicating over the direct link.The inoperative state of the direct link or the other link may refer tothe n-STR capabilities of the MLD. At 1004, the MLD may receive, from anaccess point (e.g., the AP 110 or MLD_A in FIG. 5A, 5B, 7A or 7B), anRTS frame requesting to send data to the third wireless station. At1006, the MLD may take one or more actions in response to the RTS frame.

In aspects, the second wireless station may communicate on a separateband (e.g., 5 GHz band) from the band (e.g., 6 GHz band) on which thethird wireless station communicates. In aspects, an inoperative directlink may refer to when there are no communications between the TDLSpeers on the direct link or when the direct link is no longer setupbetween the TDLS peers (e.g., a TDLS teardown process has completed).

At 1006, the MLD may either respond to the RTS frame from the accesspoint or not respond to the RTS frame. For example, taking one or moreactions at 1006 may include the MLD transmitting, to the access point, aCTS frame indicating the access point is free to transmit data to theMLD. The MLD may receive, from the access point, data via the thirdwireless station based on the transmission of the CTS frame. In certaincases, the MLD may ignore the RTS frame if the second wireless stationis communicating with the first wireless station.

In certain aspects, the RTS/CTS exchange may be specific to one or morelinks between one or more STA entities and one or more AP entities in amulti-link context. For example, the RTS/CTS exchange may be performedfor a link that is n-STR with the TDLS link. With respect to theoperations 1000A, the third wireless station may be n-STR with thesecond wireless station.

In aspects, the MLD may transmit, to the access point, indications toenable or disable the RTS/CTS exchange for n-STR links. As an example,the indication to enable or disable the RTS/CTS exchange for n-STR linksmay be indicated via a state associated with the MLD and/or a wirelessstation at the MLD. In certain cases, the state may include that the MLDhas a constraint on the wireless station (e.g., n-STR link(s)), that thewireless station is temporarily unavailable for receiving frames, orthat the MLD has setup a direct link with another wireless station. Forexample, the MLD may transmit, to the access point, a first indicationto enable transmission of the RTS frame before a transmission from theaccess point to the MLD. The MLD may transmit, to the access point, asecond indication to disable transmission of the RTS frame before atransmission from the access point to the MLD, for example, when theTDLS session is inactive. In aspects, the second indication may be anupdate to the state associated with the wireless station. For example,the updated state may include that the wireless station can receiveframes or that the direct link has been disabled or torn down. The firstor second indication may be transmitted via a control field of a MACframe, such as an aggregate control field (A-Control), for example,defined in 802.11ax standards. The control field may be a separatecontrol field (e.g., RTS-Required or RTS-Enablement) dedicated toenabling or disabling RTS/CTS exchange between the AP and an MLD. One ormore A-Control fields may be carried in the (High Efficiency) (HE)Control variant of High Throughput (HT) Control field in the MAC header.In certain aspects, the MAC frame, which carries the first or secondindication, may include a public action frame. The first or secondindication may be transmitted via a control field of a MAC header of aframe, a management frame, or a control frame.

FIG. 10B illustrates example operations 1000B of wirelesscommunications, in accordance with certain aspects of the presentdisclosure. The operations 1000B may be performed, for example, by anMLD (e.g., the non-AP MLD 304).

The operations 1000B may begin at 1008, where the MLD establishes adirect link between a first wireless station and a second wirelessstation affiliated with the MLD, for example, as described herein withrespect to FIG. 4. At 1010, the MLD may communicate with the firstwireless station (which may be affiliated with another MLD) via thedirect link, wherein the direct link is inoperative for the MLD while athird wireless station affiliated with the MLD is communicating. At1012, the MLD may transmit, to an AP MLD (or an access point affiliatedwith the AP MLD) with which the MLD has performed an association, anindication of a state associated with the MLD or one or more wirelessstations affiliated with the MLD, for example, as described herein withrespect to the operations 1000A. In certain aspects, the operations1000B may continue where the MLD may receive, from the access pointaffiliated with the AP MLD, a first frame (e.g., a RTS frame) requestingto send data to the third wireless station affiliated with the MLD inresponse to the indication of the state and take one or more actions inresponse to the first frame, for example, as described herein withrespect to the operations 1000A.

The MLD may receive the first frame via the third wireless station on achannel in which the access point affiliated with the AP MLD iscommunicating with the third wireless station. The MLD may transmit, tothe access point affiliated with the AP MLD, a second frame (e.g., a CTSframe) indicating the access point affiliated with an AP MLD is free totransmit data to the MLD. The MLD may receive, from the access pointaffiliated with an AP MLD, data via the third wireless station based onthe transmission of the second frame. The MLD may transmit, to theaccess point or the AP MLD, an update to the state indicating to disabletransmission of the first frame before a transmission from the AP MLD tothe third wireless station affiliated with the MLD.

FIG. 11 illustrates example operations 1100 of wireless communications,in accordance with certain aspects of the present disclosure. Theoperations 1100 may be performed, for example, by an access point (e.g.,the AP 110 in FIG. 1, the AP 306 affiliated with the AP MLD 302, or theAP MLD 302 in FIG. 3). The operations 1100 may be complimentary to theoperations 1000A and/or 1000B performed by the non-AP MLD.

The operations 1100 may begin, at 1102, where the access point mayreceive, from an MLD (e.g., the non-AP MLD 304), a first indication toenable transmission of an RTS frame before a transmission from theaccess point to the MLD. For example, the first indication may include astate associated with the MLD and/or a wireless station at the MLD, suchas a state indicating that the MLD has setup a direct link with anotherwireless station. At 1104, the access point may transmit, to the MLD,the RTS frame requesting to send data to one or more wireless stations(e.g., the STAs 310, 312) associated with the MLD based on the firstindication. At 1106, the access point may receive, from the MLD inresponse to the RTS frame, a CTS frame indicating the access point isfree to transmit data to the MLD. At 1108, the access point maytransmit, to the one or more wireless stations, the data if the CTSframe is received by the access point from the MLD.

In aspects, the access point may receive, from the MLD, a secondindication to disable transmission of the RTS frame before atransmission from the access point to the MLD. For example, the secondindication may include an update to the state associated with thewireless station, such as that the direct link at the MLD has beendisabled or torn down. The first or second indication may be transmittedvia a control field of a MAC frame, for example, as described hereinwith respect to the operations 1000.

FIG. 12 is a signaling flow diagram illustrating example signaling ofRTS/CTS frames to prevent or mitigate an STR state, in accordance withaspects of the present disclosure. As shown, at 1202, a first wirelessstation 120 a affiliated with a non-AP MLD 304 may transmit, to anaccess point 110, a first indication to enable transmission of an RTSframe before a transmission from the access point 110 to the firstwireless station 120 a. At 1204, a second wireless station 120 baffiliated with the non-AP MLD 304 may communicate with a third wirelessstation 120 c (which may be affiliated with a non-AP MLD or be a legacySTA) via a direct link, such as a TDLS link. At 1206, the first wirelessstation 120 a may receive an RTS frame from the access point 110. At1208, the first wireless station 120 a may transmit a CTS frame to theaccess point 110, if the direct link is inactive or inoperative. At1210, the first wireless station 120 a may receive DL data from theaccess point 110 based on the CTS frame. In certain aspects, the directlink may be busy, and the non-AP MLD 304 may ignore the RTS frame, andthe second wireless station 120 b may communicate with the thirdwireless station 120 c via the direct link at 1212. At 1214, the firstwireless station 120 a may transmit, to the access point 110, a secondindication to disable transmission of the RTS frame before atransmission from the access point 110 to the first wireless station 120a.

In certain aspects, the non-AP MLD may indicate to the AP MLD that thenon-AP MLD has entered a power save (PS) mode on n-STR links when a TDLSsession is active to prevent or mitigate an STR state.

FIG. 13A illustrates example operations 1300A of wirelesscommunications, in accordance with certain aspects of the presentdisclosure. The operations 1300A may be performed, for example, by anMLD (e.g., the non-AP MLD 304).

The operations 1300A may begin, at 1302, where the MLD may transmit, toan access point (e.g., the AP 110 or MLD_A in FIG. 5A, 5B, 7A, or 7B), afirst indication that a first wireless station (e.g., the STA 310)affiliated with the MLD is in power save mode. At 1304, the MLD maycommunicate, after transmission of the first indication, with a secondwireless station (e.g., STA 120 g in FIG. 1, STA_3 in FIGS. 5A and 5B,or MLD_R in FIGS. 7A and 7B) via a direct link between the secondwireless station and a third wireless station (e.g., the STA 312), thethird wireless station being affiliated with the MLD, where the directlink is inoperative for the MLD while the first wireless station iscommunicating, or the first wireless station is inoperative while thedirect link is operative.

In aspects, the MLD may re-enable communications with the access point.For example, the MLD may transmit, to the access point, a secondindication that the first wireless station is in an active mode (e.g.,out of power save mode and able to communicate) after ending thecommunication with the second wireless station, and in certain cases,the MLD may communicate, with the access point, via the first wirelessstation after the transmission of the second indication.

In certain aspects, the power save mode may be specific to one or morelinks between one or more STA entities and one or more AP entities in amulti-link context. For example, at 1302, the power save mode indicationmay be associated with a link that is n-STR with the TDLS link. Withrespect to the operations 1300A, the first wireless station may be n-STRwith the third wireless station.

The communication with the second wireless station via the thirdwireless station may occur when the first wireless station is notcommunicating. The communication with the access point via the firstwireless station may occur when the third wireless station is notcommunicating.

FIG. 13B illustrates example operations 1300B of wirelesscommunications, in accordance with certain aspects of the presentdisclosure. The operations 1300B may be performed, for example, by anMLD (e.g., the non-AP MLD 304).

The operations 1300B may begin at 1306, where the MLD may transmit, toan access point or an AP MLD, a first indication associated with a firstwireless station affiliated with the MLD. At 1308, the MLD maycommunicate, after transmission of the first indication, with a secondwireless station via a direct link between the second wireless stationand a third wireless station, the third wireless station beingaffiliated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

The first indication may include at least one of an indication that thefirst wireless station is in power save mode, for example, as describedherein with respect to the operations 1300A; an indication to disable afirst link to the first wireless station, for example, as furtherdescribed herein with respect to the operations 1500; or an indicationto remove a second link in a dynamic link set to the first wirelessstation, for example, as further described herein with respect to theoperations 1600. In cases where the first indication indicates the firstwireless station is in power save mode, the MLD may transmit, to theaccess point or the AP MLD, a second indication that the first wirelessstation is in active mode after ending the communication with the secondwireless station, for example, as described herein with respect to theoperations 1300A. The first indication may be transmitted via a controlfield of a MAC header of a frame, a management frame, or a controlframe, for example, as described herein with respect to the operations1000A.

FIG. 14 is a signaling flow diagram illustrating example signaling ofpower save mode to prevent or mitigate an STR state, in accordance withaspects of the present disclosure. As shown, at 1402, the first wirelessstation 120 a may transmit, to the access point 110, a first indicationthat the first wireless station 120 a is in power save mode. At 1404,the second wireless station 120 b may communicate with the thirdwireless station 120 c (which may be affiliated with a non-AP MLD or bea legacy STA) via a direct link. At 1406, the first wireless station 120a may transmit, to the access point 110, a second indication that thefirst wireless station is in an active mode after ending thecommunication between the second wireless station 120 b and the thirdwireless station 120 c. At 1408, the first wireless station 120 a mayreceive DL data from the access point 110 after transmission of thesecond indication.

In certain aspects, the non-AP MLD may disable DL aggregation (sync-PPDUoperation) on n-STR link(s) when TDLS is established on one of the n-STRlinks to prevent or mitigate an STR state.

FIG. 15 illustrates example operations 1500 of wireless communications,in accordance with certain aspects of the present disclosure. Theoperations 1500 may be performed, for example, by an MLD (e.g., thenon-AP MLD 304).

The operations 1500 may begin at 1502, where the MLD may transmit, to anaccess point (e.g., the AP 110 or MLD_A in FIG. 5A, 5B, 7A or 7B), anindication to disable a link to a first wireless station (e.g., the STA310) associated with the MLD. At 1504, the MLD may communicate, afterthe transmission of the indication, with a second wireless station(e.g., STA 120 g in FIG. 1, STA_3 in FIGS. 5A and 5B, or MLD_R in FIGS.7A and 7B) via a direct link between the second wireless station and athird wireless station (e.g., the STA 312), the third wireless stationbeing associated with the MLD, where the direct link is inoperative forthe MLD while the first wireless station is communicating, or the firstwireless station is inoperative while the direct link is operative. Thecommunication with the second wireless station via the third wirelessstation may occur when the first wireless station is not communicating.

In aspects, the indication may be transmitted via a control field of aMAC frame, for example, as described herein with respect to theoperations 1000A. The control field may be a separate control fielddedicated to enabling or disabling a link in a multi-link contextbetween the AP and an MLD.

In certain aspects, the non-AP MLD may remove the link(s) in a dynamiclink set that are n-STR with the TDLS link to prevent or mitigate an STRstate.

FIG. 16 illustrates example operations 1600 of wireless communications,in accordance with certain aspects of the present disclosure. Theoperations 1600 may be performed, for example, by an MLD (e.g., thenon-AP MLD 304).

The operations 1600 may begin at 1602, where a first MLD (e.g., thenon-AP MLD 304) may communicate, with a second MLD (e.g., the AP MLD302), via a dynamic link set comprising a plurality of links betweenfirst access points (e.g., the AP 306, 308) associated with the secondMLD and first wireless stations (e.g., the STA 310, 312) associated withthe first MLD. At 1604, the first MLD may transmit, to one or more ofthe first access points, a first indication to remove a link in thedynamic link set between the one or more of the first access points andone or more of the first wireless stations. At 1606, the first MLD maycommunicate, after the transmission of the first indication, with asecond wireless station via a direct link between the second wirelessstation and a third wireless station associated with the first MLD,where the direct link is inoperative for the first MLD while the one ormore of the first wireless stations are communicating.

In aspects, the first MLD may re-enable the links dropped from thedynamic link set with the access point when the direct link becomesinoperative. For example, the first MLD may transmit, to the one or moreof the first access points, a second indication to add the link betweenthe one or more of the first wireless stations and the one or more ofthe second wireless stations, when the direct link is inoperative. Thefirst MLD may communicate, with the one or more of the first accesspoints, via the one or more of the first wireless stations after thetransmission of the second indication.

In certain aspects, the first MLD may communicate with the second MLDvia the updated dynamic link set while the direct link is operative. Forexample, the first MLD may communicate, with a second access pointassociated with the second MLD, via a fourth wireless station associatedwith the first MLD on another link in the dynamic link set whilecommunicating with the second wireless station via the third wirelessstation. The first access points may include the second access point,and the first wireless stations may include the fourth wireless station.

The communication with the second wireless station via the thirdwireless station may occur when the first wireless station is notcommunicating. The communication with the one or more of the firstaccess points via the one or more of the first wireless stations occursmay occur the third wireless station is not communicating.

FIG. 17 is a signaling flow diagram illustrating example signaling ofdisabling/removing a link to prevent an STR state, in accordance withaspects of the present disclosure. In aspects, a dynamic link set may beformed between the first wireless stations 120 a (e.g., STA1, STA2) andthe first and second access points 110 a, 110 b affiliated with the APMLD 302. STA1 of the first wireless stations 120 a may be n-STR with thesecond wireless station 120 b, and STA2 of the first wireless stations120 a may be STR with the second wireless station 120 b.

At 1702, STA1 of the first wireless stations 120 a in the dynamic linkset may transmit a first indication to disable or remove a link betweenSTA1 of the first wireless stations 120 a and the first access point 110a. At 1704, the second wireless station 120 b may communicate with thethird wireless station 120 c via a direct link. In certain cases, at1706, STA2 of the first wireless stations 120 a may receive DL data froma second access point 110 b affiliated with the AP MLD 302 in thedynamic link set while the TDLS link is operative. In certain cases, at1708, the second wireless station 120 b may transmit a TDLS teardownframe to the third wireless station 120 c to make the direct linkinoperative. At 1710, STA1 of the first wireless stations 120 a (in thedynamic link set) may transmit a first indication to enable or add thelink between STA1 of the first wireless stations 120 a and the firstaccess point 110 a after the direct link becomes inoperative. At 1712,STA1 of the first wireless stations 120 a may receive DL data from thefirst access point 110 a, and at 1714, STA2 of the first wirelessstations 120 a may receive DL data from the second access point 110 b.

In certain cases, during the TDLS discovery and setup process, when anintermediate AP is affiliated with an AP MLD, the Discovery Requestframe (relayed via the AP MLD) may be received on the wrong link by therecipient non-AP MLD. For example, suppose a wireless station (e.g., alegacy STA or a STA affiliated with an MLD) transmits a DiscoveryRequest frame on the 5 GHz band, and the AP MLD relays the DiscoveryRequest frame to a non-AP MLD on the 2.4 GHz band or 6 GHz band. Such ascenario may be referred to a cross-over of a request/response at the APMLD. Similar to the cross-over scenario, an initiator/responder non-APMLD may transmit a TDLS request/response on a different link than adesired link for direct link communications. Such a scenario may bereferred to a link mismatch scenario. It may be unclear to the non-APMLD which band is intended for the TDLS link between the wirelessstation and the non-AP MLD, resulting in a failure to setup a TDLS linkbetween the initiator STA and the non-AP MLD.

Certain aspects of the present disclosure provide techniques foridentifying/selecting one or more links between TDLS peer STAs duringthe TDLS discovery and setup process. An initiating MLD may include themulti-link IE in a discovery request frame to indicate that the MLDsupports TDLS over multiple links and identify specific link(s) for theTDLS session. In aspects, the multi-link IE in the discovery requestframe or lack thereof may indicate if the initiator is an MLD or alegacy STA. That is, the absence of the multi-link IE in the discoveryrequest frame may indicate that the initiator STA is a legacy STA. Ifthe recipient is a legacy STA, the legacy STA may ignore the multi-linkIE, and the legacy STA may send a Discovery Response frame directly tothe initiator on the same link on which the STA received the Request.

If the TDLS initiator is a legacy STA, the legacy STA may identify alink for direct link communications in the discovery request frame. Forexample, the BSSID field in the Link Identifier IE may identify thelink, or the link identifier IE may include a separate field thatidentifies the link for direct link communications. An MLD STA may senda Discovery Response frame directly to the initiator STA on therequested link.

The techniques described herein for identifying/selecting TDLS links mayenable TDLS communications between MLDs and/or between an MLD and alegacy STA, for example, in cases where the response/request is crossedover at an AP MLD to a non-AP MLD, or where the response/request istransmitted on a different link by the initiator/responder peer STA thanthe requested/desired link.

FIG. 18 illustrates example operations 1800 of wireless communications,in accordance with certain aspects of the present disclosure. Theoperations 1800 may be performed, for example, by a wireless station(e.g., the STA 120 a or the non-AP MLD 304).

The operations 1800 may begin at 1802, where a first wireless station(e.g., the STA_3 in FIG. 5B) may transmit, to a second wireless station(e.g., the STA_1 of MLD_S in FIG. 5B) via an access point (e.g., theMLD_A in FIG. 5B), a request to discover a peer wireless station (suchas the second wireless station) for direct link communications betweenthe first wireless station and the second wireless station, wherein therequest indicates a link for communications between the first wirelessstation and the second wireless station. At 1804, the first wirelessstation may communicate directly with the second wireless station viathe link indicated in the request.

In certain aspects, the second wireless station may respond to therequest via the link indicated in the request. For example, the firstwireless station may receive, from the second wireless station, aresponse responsive to the request via the link indicated in therequest. The response may include a TDLS Discovery Request frame.

In aspects, the request may include a TDLS Discovery Request frame. Therequest may indicate the link via a link identifier associated with thelink. That is, a specific value, which may represent the link as thelink identifier, may be associated with the link, and the request mayinclude the link identifier. In aspects, the request may include thelink identifier IE (for example, as depicted in FIG. 6), which mayinclude a field that indicates the link. The BSSID field may include (orbe set to) a value indicating the link, where the value may be differentfrom one of the BSSIDs in the wireless network or the same as one of theBSSIDs in the wireless network. For example, BSSID field may be set tothe BSSID of the corresponding affiliated AP of the AP MLD that isoperating on the link where the TDLS direct link was established. Inaspects, the link identifier IE may include a separate field (separatefrom the fields depicted in FIG. 6) that indicates/identifies the link.For example, the link identifier IE may include a link identifier field,which provides unique value associated with the link between the TDLSpeer STAs.

In certain aspects, the second wireless station may be associated withan MLD (e.g., the MLD_S in FIG. 5B). That is, the second wirelessstation may be a STA entity affiliated with an MLD. The indication ofthe link in the request may enable the second wireless station to setupa direct link on the requested link if the intermediate AP relays therequest on a different link than the requested link.

As discussed above, various aspects for identifying/selecting TDLS linksmay be applied to an MLD. An initiator STA of an MLD may include amulti-link IE (e.g., depicted in FIG. 19) in a discovery request frameto identify requested link(s) for direct link communications.

In certain aspects, if the initiator and the responder in a TDLSdiscovery/setup process are MLDs and the Discovery Request includes amulti-link IE, the responder MLD may transmit a single DiscoveryResponse frame. The multi-link IE in the request may enable theresponder MLD to setup a direct link on the requested link if theintermediate AP relays the request on a different link than therequested link. In aspects, the Discovery Response frame from theresponder MLD may have an indication of the requested link. For example,the BSSID field in the Link Identifier element identify the requestedlink, or a separate field in the Link Identifier element may identifythe requested link.

For example, with respect to the operations 400, the first MLD mayreceive, from the first wireless station (which may be a legacy STA or aSTA affiliated with an MLD) via an access point, a request to setup thedirect link (e.g., the request to setup may include a Setup Requestframe) or to discover a peer wireless station (such as the first MLD)(e.g., the request to discover may include a Discovery Request frame),where the request may indicate a first link for communications betweenthe first wireless station and the second wireless station. The requestmay indicate the first link via a link identifier associated with thefirst link. For example, the BSSID field in a link identifier element ofthe request may include (or may be set to) a value indicating the firstlink, where the value may be the link identifier. In certain aspects, amulti-link element (e.g., depicted in FIG. 19) indicates one or morelinks including the first link in the request, for example, the link IDfield. The multi-link element may also indicate capability informationassociated with the first link. An example of capability information maybe that the link is n-STR or STR. Capability information may include asone or more fields in the per-STA profile sub-element.

In aspects, the initiator/responder MLD may send a TDLS Setup Request ora Discovery Response frame on the requested link after receiving aDiscovery Request/Response frame. For example, with respect to theoperations 400, the first MLD may transmit, to the first wirelessstation, a response responsive to the request via the first linkindicated in the request. The communication with the first wirelessstation may include the first MLD communicating with the first wirelessstation via the first link indicated in the request. In certain aspects,the response to the discovery/setup request may indicate thedesired/requested link for direct link communications. The response mayinclude an indication of the first link or a second link different fromthe first link. A BSSID field in the Link Identifier element of theResponse frame may identify the requested link or a different/separatelink. For example, a BSSID field in a link identifier element of theresponse may include (or be set to) a value indicating the first link orthe second link. As an example, the BSSID field may be set to the MACaddress of an AP on the channel or band associated with the requestedlink. That is, a specific AP may be communicating on the same channel orband as the requested/desired link for direct link communications, andthe MAC address of that specific AP may be used in the BSSID field inthe link identifier element to represent the desired/requested link.

In certain cases, the MLD may receive, from the access point, therequest via a different link than the link indicated in the request. Forexample, the reception of the request may include receiving the requestfrom the access point on a second link, which may be different orseparate from the first link. For example, the second link may be on adifferent channel or a different band than a channel or a bandassociated with the first link, of the second link may be with adifferent AP from which received the request from the initiator STA. Inother words, the first link may be associated with a specific channel orband in the frequency domain. The initiator STA may transmit the requeston a first channel/band associated with the first link to a first AP,and a second AP may relay the request on a second channel/bandassociated with the second link. In certain aspects, the responder MLDmay not respond to a Discovery Request frame if the responder MLD is notoperating on the requested link or receives the request on a differentlink than the requested link. For example, the first MLD may ignore therequest based on the request being received on the second link, e.g., adifferent link, a different channel, or a different band than therequested first link.

In certain aspects, the initiator MLD may receive a Setup Response on adifferent link than requested, and the various indications of therequested link may enable the initiator MLD to complete the direct linksetup. For example, with respect to the operations 400, the first MLDmay receive, from the first wireless station via an access point, aresponse responsive to a request to setup the direct link (e.g., a SetupResponse frame), where the request indicates a first link forcommunications between the first wireless station and the one or moresecond wireless stations, and where the response is received via asecond link, which may be different from the first link. The indicationof the first link may include a BSSID field in the link identifierelement or a link ID in the multi-link element. The first MLD mayidentify the first link in the response, and the communication with thefirst wireless station may include the first MLD communicating with thefirst wireless station via the first link indicated in the response.

In certain aspects, the initiator/responder MLD may transmit a SetupRequest/Response on different link than the desired/request link, andthe various indications of the requested link may enable the recipientpeer MLD to complete the direct link setup. For example, with respect tothe operations 400, the first MLD may transmit, to the first wirelessstation via an access point, a request to setup the direct link (e.g., aSetup Request frame) or a response to the request (e.g., a SetupResponse frame), where the request or the response may indicate a firstlink for communications between the first wireless station and the oneor more second wireless stations, and where the request or the responsemay be transmitted via a second link. The indication in the response orrequest may enable the recipient peer MLD to identify thedesired/requested link for direct link communications. The indication ofthe first link may include a BSSID field in the link identifier elementor a link ID in the multi-link element. The communication with the firstwireless station may include the first MLD communicating with the firstwireless station via the first link indicated in the response or therequest.

In certain aspects, the initiator non-AP MLD may send more than oneDiscovery Request frame with the BSSID field in the Link Identifierelement set to the BSSID of APs on each link that has an operationallink. As an example, the initiator non-AP MLD may transmit more than oneTDLS Discovery Request frames, where each Request frame has a differentBSSID value (e.g., one of the BSSIDs corresponding to an AP of the APMLD that is used to establish the link) in the BSSID field LinkIdentifier element. Transmission of multiple Discovery Request frames toseparate links may enable the initiating non-AP MLD to find at least onelink common with the responding STA/MLD and to establish a TDLS sessionwith the common link(s). For example, with respect to the operations400, the first MLD may transmit, to one of the third wireless stationsassociated with the second MLD via an access point, a first request todiscover a peer wireless station for the direct link, where the firstrequest indicates a first link for communications between the one of thethird wireless stations and one of the second wireless stationsassociated with the first MLD. After sending the first request, thefirst MLD may wait a certain duration and determine that the durationhas passed without receiving a response to the first request. The firstMLD may transmit, to another one of the third wireless stationsassociated with the second MLD via the access point, a second request todiscover a peer wireless station for the direct link, where the secondrequest indicates a second link for communications between the other oneof the third wireless stations and another one of the second wirelessstations associated with the first MLD. At 406, the communication withthe first wireless station may include the first MLD communicating withthe first wireless station via the second link.

In certain aspects, the responder MLD may send multiple discoveryresponses to a request for a single link. For example, the responder MLDmay send a Discovery Response frame on the requested link if operatingon that link and send unsolicited discovery responses on other links,which may or may not be already setup for multi-link communications. Thelinks that are already setup may be referred to as overlapping links.Suppose that MLD1 and MLD2 have performed multi-link (ML) setup for adifferent set of links, such that MLD1 and MLD2 have performed ML setupfor 5 and 6 GHz bands, and MLD2 has the 2.4 GHz band setup for the MLcommunications. In response to a Discovery Request frame on the 5 GHzband, MLD2 may send a Discovery Response frame on the 5 GHz band as wellas unsolicited responses on the 2.4 and 6 GHz bands. The initiatorSTA/MLD (e.g., MLD1) may select one or more links (including theoverlapping links) based on certain criteria and send a TDLS setup framewith the selection of links. In the above example, the MLD1 may selectlinks among the 5 and 6 GHz bands as MLD1 is inoperative on the 2.4 GHzband and does not receive that particular unsolicited Discovery Responseframe. In aspects, the criteria for link selection may be based on asignal quality associated with the Discovery Response frames, where thesignal quality may include signal-to-noise ratio (SNR),signal-to-interference plus noise ratio (SINR), signal-to-noise plusdistortion ratio (SNDR), and/or a received signal strength indicator(RSSI) of the Discovery Response frames. The initiator STA may selectmore than one overlapping link for performing multi-link TDLS.

As an example of the responder MLD sending multiple discovery responses,with respect to the operations 400, the first MLD may transmit directly,to the first wireless station associated with the second MLD, a firstresponse responsive to the request via the first link indicated in therequest. The first MLD may transmit directly, to one or more of thethird wireless stations associated with the second MLD, a secondresponse responsive to the request via second link. The first MLD maycommunicate with the one or more third wireless stations via the secondlink indicated in the second response, and the communication with thefirst wireless station may include the first MLD communicating with thefirst wireless station via the first link indicated in the firstresponse.

As an example of the initiator MLD receiving multiple discoveryresponses, with respect to the operations 400, the first MLD mayreceive, from the third wireless stations, discovery response frames viaone or more of the plurality of links. The first MLD may select a linkamong a plurality of links between the second wireless stations and thethird wireless stations. The selection of the link may be based on asignal quality of the discovery response frames, where signal qualityincludes an SNR, SINR, SNDR, or RSSI of the discovery response frames.The first MLD may transmit, to one or more of the third wirelessstations, a request to setup the direct link on the selected link. Inaspects, the selected link may include two or more of the plurality oflinks.

With respect to the operations 400, the various aspects described hereinwhere the first MLD receives or transmits a Discovery Request/Responseframe or a Setup Request/Response frame may be performed at 402.

FIG. 19 is a diagram illustrating an example multi-link informationelement format, in accordance with certain aspects of the presentdisclosure. As shown, the multi-link information element may include alink identifier (ID) field associated with a per-STA profilesub-element. In aspects, the per-STA sub-elements may be populated forall or some of the STAs affiliated with an MLD, and each of the per-STAsub-elements may identify a link for communications (such as direct linkcommunication) via the link identifier field, which may be set to aunique value for a specific link. The link ID field may be used in thediscovery request frame to indicate one or more requested links fordirect link communications.

FIG. 20 is a signaling flow diagram illustrating example signaling ofcross-over of a discovery request, in accordance with aspects of thepresent disclosure. At 2002, STA3 of a second MLD 304 b (e.g., a non-APMLD) may transmit a discovery request frame to the AP 110 a of the APMLD 302, where the discovery request frame indicates a link forcommunications between the second wireless station 120 b and STA3. Forexample, the discovery request frame may include a multi-link element ora link identifier element that identifies the link for direct linkcommunications as described herein. At 2004, the AP 110 b may relay thediscovery request frame to the first wireless station 120 a of the firstMLD 304 a. At 2006, the first MLD 304 a may identify the requested linkin the discovery request frame for the direct link communications withone of the third wireless stations 120 c (e.g., STA3), and the secondwireless station 120 b of the first MLD 304 a may transmit a discoveryresponse frame to STA3 of the third wireless stations 120 c via therequest link indicated in the discovery request. At 2008, the secondwireless station 120 b may communicate directly with STA3 via therequested link.

In certain cases, at 2010, the first wireless station 120 a may alsotransmit a discovery response frame to STA4 of the third wirelessstations 120 c to indicate that multiple links can be setup for thedirect link. The unsolicited discovery response frame at 2010 may besent via an overlapping link that is setup for multi-linkcommunications. That is, a multi-link may already be setup between thefirst wireless station 120 a and the AP MLD 302 when the first wirelessstation 120 a sends the discovery response frame at 2010. At 2012, thefirst wireless station 120 a may communicate directly with STA4 via thelink indicated in the discovery response frame at 2010. In certaincases, the communications at 2008 and 2012 may be concurrent and/oraggregated with each other to facilitate desirable throughputs andlatencies between the MLDs 304 a, 304 b.

While the example depicted in FIG. 20 is described herein with respectto establishing a direct link between MLDs 304 a, 304 b and a cross-overof a discovery request frame to facilitate understanding, aspects of thepresent disclosure may also be applied to establishing a direct linkbetween an MLD and a legacy station and handling a cross-over of otherTDLS frames (e.g., a Discovery Response frame, a Setup Request frame, orSetup Response frame) at the AP or a link mismatch between MLD peers.The various aspects described herein with respect to handling across-over of a Discovery Request frame may also applied to thecross-over/mismatch of a Discovery Response frame, a Setup Requestframe, or a Setup Response frame. For example, each of these frames mayinclude an indication of the requested/desired link for direct linkcommunications in case the frame is relayed to a peer STA of an MLD on adifferent link than the requested/desired link. The indication mayinclude, for example, a BSSID field in a link identifier element or alink ID field in a multi-link element.

While various aspects are described with respect to an MLD communicatingwith a STA/AP, transmitting a frame to a STA/AP, or receiving a framefrom a STA/AP to facilitate understanding, such aspects of the presentdisclosure may include a STA/AP entity (e.g., the STA 310, 312)affiliated with the MLD communicating with the STA/AP, transmitting aframe to the STA/AP, or receiving a frame from the STA/AP.

FIG. 21 illustrates a communications device (e.g., a non-AP MLD or aSTA) 2100 that may include various components (e.g., corresponding tomeans-plus-function components) configured to perform operations for thetechniques disclosed herein, such as the operations illustrated in FIGS.4, 10, 13, 15, 16, and 18. The communications device 2100 includes aprocessing system 2102 coupled to a transceiver 2108 (e.g., atransmitter and/or a receiver). The transceiver 2108 is configured totransmit and receive signals for the communications device 2100 via anantenna 2110, such as the various signals as described herein. Theprocessing system 2102 may be configured to perform processing functionsfor the communications device 2100, including processing signalsreceived and/or to be transmitted by the communications device 2100.

The processing system 2102 includes a processor 2104 coupled to acomputer-readable medium/memory 2112 via a bus 2106. In certain aspects,the computer-readable medium/memory 2112 is configured to storeinstructions (e.g., computer-executable code) that when executed by theprocessor 2104, cause the processor 2104 to perform the operationsillustrated in FIGS. 4, 10, 13, 15, 16, and 18, or other operations forperforming the various techniques discussed herein for handling TDLS inMLO. In certain aspects, computer-readable medium/memory 2112 storescode for outputting, for transmission 2114, code for obtaining 2116,and/or code for communicating 2118. In certain aspects, the processingsystem 2102 has circuitry 2122 configured to implement the code storedin the computer-readable medium/memory 2112. In certain aspects, thecircuitry 2122 is coupled to the processor 2104 and/or thecomputer-readable medium/memory 2112 via the bus 2106. For example, thecircuitry 2122 includes circuitry for outputting, for transmission,2124, circuitry for obtaining 2126, and/or circuitry for communicating2128.

FIG. 22 illustrates a communications device (e.g., an AP MLD or an AP)2200 that may include various components (e.g., corresponding tomeans-plus-function components) configured to perform operations for thetechniques disclosed herein, such as the operations illustrated in FIGS.8 and 11. The communications device 2200 includes a processing system2202 coupled to a transceiver 2208 (e.g., a transmitter and/or areceiver). The transceiver 2208 is configured to transmit and receivesignals for the communications device 2200 via an antenna 2210, such asthe various signals as described herein. The processing system 2202 maybe configured to perform processing functions for the communicationsdevice 2200, including processing signals received and/or to betransmitted by the communications device 2200.

The processing system 2202 includes a processor 2204 coupled to acomputer-readable medium/memory 2212 via a bus 2206. In certain aspects,the computer-readable medium/memory 2212 is configured to storeinstructions (e.g., computer-executable code) that when executed by theprocessor 2204, cause the processor 2204 to perform the operationsillustrated in FIGS. 8 and 11, or other operations for performing thevarious techniques discussed herein for handling TDLS in MLO. In certainaspects, computer-readable medium/memory 2212 stores code for obtaining2214, code for outputting, for transmission, 2216, and/or code forrelaying 2218. In certain aspects, the processing system 2202 hascircuitry 2222 configured to implement the code stored in thecomputer-readable medium/memory 2212. In certain aspects, the circuitry2222 is coupled to the processor 2204 and/or the computer-readablemedium/memory 2212 via the bus 2206. For example, the circuitry 2222includes circuitry for obtaining 2224, circuitry for outputting, fortransmission, 2226, and/or circuitry for relaying 2228.

Example Aspects

In addition to the various aspects described above, aspects of specificcombinations are within the scope of the disclosure, some of which aredetailed below:

Aspect 1: A method of wireless communications by a first multi-linkdevice (MLD), comprising: transmitting, to a first wireless station viaa direct link between the first wireless station and one or more secondwireless stations associated with the first MLD, a data frame comprisinga transmitter address field set to an address of the first MLD, which isone of a plurality of addresses associated with the first MLD and thesecond wireless stations being associated with the first MLD formulti-link operations; and communicating with the first wireless stationvia the direct link.

Aspect 2: The method of Aspect 1, wherein the address of the first MLDcomprises a multi-link logical medium access control (MAC) address, andthe plurality of addresses includes the multi-link logical MAC addressand MAC addresses associated with the second wireless stations.

Aspect 3: The method according to any of Aspects 1-2, further comprisingtransmitting, to the first wireless station via an access point, arequest to discover a peer wireless station for the direct link, whereinthe request comprises a link identifier element having a direct linkinitiator address set as the address of the MLD.

Aspect 4: The method according to any of Aspects 1-3, further comprisingtransmitting, to the first wireless station via an access point, arequest to setup the direct link, wherein the request comprises a linkidentifier element having a direct link initiator address set as theaddress of the first MLD.

Aspect 5: The method of according to any of Aspects 1-4, furthercomprising transmitting, to the first wireless station, a responseresponsive to a request to discover a peer wireless station for thedirect link, wherein the response comprises a link identifier elementhaving a direct link responder address set as the address of the MLD.

Aspect 6: The method of according to any of Aspects 1-5, furthercomprising: transmitting, to the first wireless station via an accesspoint, a response responsive to a request to setup the direct link,wherein the response comprises a link identifier element having a directlink responder address set as the address of the MLD.

Aspect 7: The method according to any of Aspects 1-6, furthercomprising: transmitting, to the first wireless station, a discoveryresponse comprising the transmitter address field set to the address ofthe first MLD.

Aspect 8: The method of Aspect 7, further comprising: receiving, fromthe first wireless station via an access point, a request to discover apeer wireless station for the direct link; and wherein the transmissionof the discovery response is responsive to the request.

Aspect 9: The method according to any of Aspects 1-8, wherein thecommunication with the first wireless station via the direct linkcomprises: receiving, from the first wireless station via the directlink, a frame comprising a receiver address field set to the address ofthe first MLD.

Aspect 10: The method according to any of Aspects 1-9, furthercomprising: transmitting, to a wireless node, a first frame via one ofthe second wireless stations in a direction away from the first wirelessstation based on the direct link being operative; and wherein thecommunication with the first wireless station comprises transmitting, tothe first wireless station, a second frame via another one of the secondwireless stations in a direction towards the first wireless station.

Aspect 11: The method according to any of Aspects 1-10, furthercomprising: generating an encryption key based at least in part on theaddress of the first MLD; transmitting, to the first wireless station,an indication of the encryption key; and wherein the communication withthe first wireless station comprises communicating encrypted frames withthe first wireless station based on the encryption key.

Aspect 12: The method according to any of Aspects 1-11, wherein thedirect link is a tunneled direct link.

Aspect 13: The method according to any of Aspects 1-12, wherein the dataframe comprises a MAC header including the transmitter address field.

Aspect 14: The method according to any of Aspects 1-13, wherein thefirst wireless station is associated with a second MLD for multi-linkcommunications with the first MLD, and the second MLD further has two ormore third wireless stations, including the first wireless station,being associated therewith for multi-link communications with the firstMLD.

Aspect 15: The method of Aspect 14, wherein: the direct link comprises aplurality of tunneled direct link sessions; and each of the plurality oftunneled direct link sessions is associated with a separate link betweenone of the second wireless stations and one of the third wirelessstations.

Aspect 16: The method of Aspect 14, wherein: the direct link comprises asingle tunneled direct link session; and a plurality of links betweenthe second wireless stations and the third wireless stations areassociated with the single tunneled direct link session.

Aspect 17: The method according to any of Aspects 1-16, furthercomprising: transmitting, to the first wireless station, an indicationto setup the direct link as a multi-link direct link, wherein thecommunication with the first wireless station via the direct linkcomprises communicating with the first wireless station via one or morelinks of the multi-link direct link based on the indication.

Aspect 18: The method of Aspect 17, wherein the indication comprises atleast one of: a basic service set identifier (BSSID) field comprises avalue indicating to setup the direct link as the multi-link direct link;or a multi-link element in a direct link discovery frame or a directlink setup frame.

Aspect 19: The method of Aspect 18, wherein the value comprises a linkidentifier associated with the one or more links.

Aspect 20: The method of Aspect 18, wherein the multi-link elementincludes: a first indication having an identifier of the direct link ina station profile sub-element associated with at least one of the secondwireless stations; or a second indication of one or more capabilities ofthe second wireless stations associated with links between the secondwireless stations and the third wireless stations.

Aspect 21: The method according to any of Aspects 1-20, furthercomprising: receiving, from the first wireless station via an accesspoint, a request to setup the direct link or to discover a peer wirelessstation for the direct link, wherein the request indicates a first linkfor communications between the first wireless station and the one ormore second wireless stations.

Aspect 22: The method of Aspect 21, wherein the request indicates thefirst link via a link identifier associated with the first link.

Aspect 23: The method according to any of Aspects 21-22, wherein a basicservice set identifier (BSSID) field in a link identifier element of therequest comprises a value indicating the first link.

Aspect 24: The method according to any of Aspects 21-22, wherein amulti-link element indicates the first link in the request.

Aspect 25: The method of Aspect 24, wherein the multi-link elementfurther indicates capability information associated with the first link.

Aspect 26: The method of Aspect 21, further comprising: transmitting, tothe first wireless station, a response responsive to the request via thefirst link indicated in the request; and wherein the communication withthe first wireless station comprises communicating with the firstwireless station via the first link indicated in the request.

Aspect 27: The method of Aspect 26, wherein the response includes anindication of the first link.

Aspect 28: The method of Aspect 27, wherein a BSSID field in a linkidentifier element of the response comprises a value indicating thefirst link.

Aspect 29: The method according to any of Aspects 21-28, wherein thereception of the request comprises receiving the request from the accesspoint on a second link.

Aspect 30: The method of Aspect 29, further comprising ignoring therequest based on the request being received on the second link based onthe first link being inoperative.

Aspect 31: The method according to any of Aspects 1-30, furthercomprising: receiving, from the first wireless station via an accesspoint, a response responsive to a request to setup the direct link,wherein the request indicates a first link for communications betweenthe first wireless station and the one or more second wireless stations,wherein the response is received via a second link; and wherein thecommunication with the first wireless station comprises communicatingwith the first wireless station via the first link indicated in theresponse.

Aspect 32: The method according to any of Aspects 1-31, furthercomprising: transmitting, to the first wireless station via an accesspoint, a request to setup the direct link or a response to the request,wherein the request or the response indicates a first link forcommunications between the first wireless station and the one or moresecond wireless stations, wherein the request or the response istransmitted via a second link; and wherein the communication with thefirst wireless station comprises communicating with the first wirelessstation via the first link indicated in the response or the request.

Aspect 33: The method of Aspect 21, further comprising: transmittingdirectly, to the first wireless station associated with the second MLD,a first response responsive to the request via the first link indicatedin the request; transmitting directly, to one or more of the thirdwireless stations associated with the second MLD, a second responseresponsive to the request via second link; communicating with the one ormore third wireless stations via the second link; and wherein thecommunication with the first wireless station comprises communicatingwith the first wireless station via the first link indicated in therequest.

Aspect 34: The method of Aspect 14, further comprising: selecting atleast one link among a plurality of links between the second wirelessstations associated with the first MLD and the third wireless stationsassociated with the second MLD; and transmitting, to one or more of thethird wireless stations associated with the second MLD, a request tosetup the direct link on the selected at least one link.

Aspect 35: The method of Aspect 34, further comprising: receiving, fromthe third wireless stations associated with the second MLD, discoveryresponse frames via one or more of the plurality of links; and whereinthe selection of the at least one link is based on a signal qualityassociated with the discovery response frames.

Aspect 36: The method according to any of Aspects 34-35, wherein theselected at least one link includes two or more of the plurality oflinks.

Aspect 37: The method of Aspect 14, further comprising: transmitting, toone of the third wireless stations associated with the second MLD via anaccess point, a first request to discover a peer wireless station forthe direct link, wherein the first request indicates a first link forcommunications between the one of the third wireless stations and one ofthe second wireless stations associated with the first MLD; determiningthat a duration has passed without receiving a response to the firstrequest; and transmitting, to another one of the third wireless stationsassociated with the second MLD via the access point, a second request todiscover a peer wireless station for the direct link based on thedetermination, wherein the second request indicates a second link forcommunications between the other one of the third wireless stations andanother one of the second wireless stations associated with the firstMLD.

Aspect 38: A method of wireless communications by a multi-link device(MLD), comprising: communicating with a first wireless station via adirect link between the first wireless station and a second wirelessstation, the second wireless station being associated with the MLD,wherein the direct link is inoperative for the MLD while a thirdwireless station associated with the MLD is communicating; receiving,from an access point, a request-to-send (RTS) frame requesting to senddata to the third wireless station associated with the MLD; and takingone or more actions in response to the RTS frame.

Aspect 39: The method of Aspect 38, wherein taking one or more actionscomprises: transmitting, to the access point, a clear-to-send (CTS)frame indicating the access point is free to transmit data to the MLD;and receiving, from the access point, data via the third wirelessstation based on the transmission of the CTS frame.

Aspect 40: The method of Aspect 38, wherein taking one or more actionscomprises: ignoring the RTS frame if the second wireless station iscommunicating with the first wireless station.

Aspect 41: The method according to any of Aspects 39-40, furthercomprising: transmitting, to the access point, a first indication toenable transmission of the RTS frame before a transmission from theaccess point to the MLD.

Aspect 42: The method according to any of Aspects 38-41, furthercomprising: transmitting, to the access point, a second indication todisable transmission of the RTS frame before a transmission from theaccess point to the MLD.

Aspect 43: The method according to any of Aspects 41-42, wherein thefirst or second indication is transmitted via a control field of a MACframe.

Aspect 44: The method of Aspect 43, wherein the MAC frame comprises apublic action frame.

Aspect 45: A method of wireless communications by an access point,comprising: receiving, from a multi-link device (MLD), a firstindication to enable transmission of a request-to-send (RTS) framebefore a transmission from the access point to the MLD; transmitting, tothe MLD, the RTS frame requesting to send data to one or more wirelessstations associated with the MLD based on the first indication; andtransmitting, to the one or more wireless stations, the data if aclear-to-send (CTS) frame is received by the access point from the MLD.

Aspect 46: The method of Aspect 45, further comprising: receiving, fromthe MLD, a second indication to disable transmission of the RTS framebefore a transmission from the access point to the MLD.

Aspect 47: The method of according to any of Aspects 45-46, wherein thefirst or second indication is received via a control field of a MACframe.

Aspect 48: The method of Aspect 47, wherein the MAC frame comprises apublic action frame.

Aspect 49: A method of wireless communications by a multi-link device(MLD), comprising: transmitting, to an access point, a first indicationthat a first wireless station associated with the MLD is in power savemode; and communicating, after transmission of the first indication,with a second wireless station via a direct link between the secondwireless station and a third wireless station, the third wirelessstation being associated with the MLD, wherein the direct link isinoperative for the MLD while the first wireless station iscommunicating.

Aspect 50: The method of Aspect 49, further comprising: transmitting, tothe access point, a second indication that the first wireless station isin active mode after ending the communication with the second wirelessstation.

Aspect 51: The method of Aspect 50, further comprising: communicating,with the access point, via the first wireless station after thetransmission of the second indication.

Aspect 52: The method of any of Aspects 49-51, wherein: thecommunication with the second wireless station via the third wirelessstation occurs when the first wireless station is not communicating; orthe communication with the access point via the first wireless stationoccurs when the third wireless station is not communicating.

Aspect 53: A method of wireless communications by a multi-link device(MLD), comprising: transmitting, to an access point, an indication todisable a link to a first wireless station associated with the MLD; andcommunicating, after the transmission of the indication, with a secondwireless station via a direct link between the second wireless stationand a third wireless station, the third wireless station beingassociated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

Aspect 54: The method of Aspect 53, wherein: the communication with thesecond wireless station via the third wireless station occurs when thefirst wireless station is not communicating.

Aspect 55: The method of any of Aspects 53-54, wherein the indication istransmitted via a control field of a medium access control (MAC) frame.

Aspect 56: The method of Aspect 55, wherein the MAC frame comprises apublic action frame.

Aspect 57: A method of wireless communications by a first multi-linkdevice (MLD), comprising: communicating, with a second MLD, via adynamic link set comprising a plurality of links between first accesspoints associated with the second MLD and first wireless stationsassociated with the first MLD; transmitting, to one or more of the firstaccess points, a first indication to remove a link in the dynamic linkset between the one or more of the first access points and one or moreof the first wireless stations; and communicating, after thetransmission of the first indication, with a second wireless station viaa direct link between the second wireless station and a third wirelessstation associated with the first MLD, wherein the direct link isinoperative for the first MLD while the one or more of the firstwireless stations are communicating.

Aspect 58: The method of Aspect 57, further comprising: transmitting, tothe one or more of the first access points, a second indication to addthe link between the one or more of the first wireless stations and theone or more of the second wireless stations, when the direct link isinoperative.

Aspect 59: The method of Aspect 58, further comprising: communicating,with the one or more of the first access points, via the one or more ofthe first wireless stations after the transmission of the secondindication; and communicating, with a second access point associatedwith the second MLD, via a fourth wireless station associated with thefirst MLD on another link in the dynamic link set while communicatingwith the second wireless station, wherein the first access pointscomprise the second access point, and the first wireless stationscomprise the fourth wireless station.

Aspect 60: The method of any of Aspects 57-59, wherein: thecommunication with the second wireless station via the third wirelessstation occurs when the first wireless station is not communicating; orthe communication with the one or more of the first access points viathe one or more of the first wireless stations occurs when the thirdwireless station is not communicating.

Aspect 61: A method of wireless communications by a first multi-linkdevice (MLD), comprising: receiving, from a second MLD via a firstaccess point associated with the first MLD, one or more first framesrelated to establishing a direct link between the second MLD and a firstwireless station, wherein the first wireless station does not supportmulti-link operations; and relaying, to the first wireless station viathe first access point, the one or more first frames, wherein the one ormore first frames include a source address field set to an address of asecond wireless station associated with the second MLD.

Aspect 62: The method of Aspect 61, further comprising: mapping anaddress of the second MLD to the address of the second wireless stationbased on the first wireless station not supporting multi-linkoperations, wherein the transmission of the one or more first frames isbased on the mapping between the address of the second MLD and theaddress of the second wireless station.

Aspect 63: The method of Aspect 62, further comprising: receiving, fromthe first wireless station via the access point, one or more secondframes related to the establishment of the direct link; and relaying, tothe second MLD, the one or more second frames, wherein the one or moresecond frames include a destination address field set to the address ofthe second wireless station.

Aspect 64: The method of Aspect 63, further comprising: receiving, froma third wireless station associated with the second MLD via a secondaccess point associated with the first MLD, one or more third framesrelated to establishing the direct link between the second MLD and thefirst wireless station, wherein the one or more first frames include atransmitter address field set to an address of the third wirelessstation; relaying, to the first wireless station via the first accesspoint, the one or more third frames, wherein the one or more thirdframes include a source address field set to the address of the secondwireless station; and wherein the reception of the one or more firstframes comprises receiving the one or more first frames from the secondwireless station associated with the second MLD.

Aspect 65: A method of wireless communications by a first wirelessstation, comprising: transmitting, to a second wireless station via anaccess point, a request to discover the second wireless station fordirect link communications between the first wireless station and thesecond wireless station, wherein the request indicates a link forcommunications between the first wireless station and the secondwireless station; and communicating directly with the second wirelessstation via the link indicated in the request.

Aspect 66: The method of Aspect 65, further comprising: receiving, fromthe second wireless station, a response responsive to the request viathe link indicated in the request.

Aspect 67: The method according to any of Aspects 65-66, wherein therequest includes a Discovery Request frame.

Aspect 68: The method according to any of Aspects 65-67, wherein thesecond wireless station is associated with a multi-link device.

Aspect 69: The method according to any of Aspects 65-68, wherein therequest indicates the link via a link identifier associated with thelink.

Aspect 70: The method according to any of Aspects 65-69, wherein a basicservice set identifier (BSSID) field in a link identifier element of therequest comprises a value indicating the link.

Aspect 71: A first multi-link device (MLD), comprising: a transceiverconfigured to transmit, to a first wireless station via a direct linkbetween the first wireless station and one or more second wirelessstations associated with the first MLD, a data frame comprising atransmitter address field set to an address of the first MLD, which isone of a plurality of addresses associated with the first MLD and thesecond wireless stations being associated with the first MLD formulti-link operations; and communicate with the first wireless stationvia the direct link.

Aspect 72: A multi-link device (MLD), comprising: a transceiverconfigured to communicate with a first wireless station via a directlink between the first wireless station and a second wireless station,the second wireless station being associated with the MLD, wherein thedirect link is inoperative for the MLD while a third wireless stationassociated with the MLD is communicating and receive, from an accesspoint, a request-to-send (RTS) frame requesting to send data to thethird wireless station associated with the MLD; and a processing systemconfigured to take one or more actions in response to the RTS frame.

Aspect 73: A multi-link device (MLD), comprising: a transceiverconfigured to: transmit, to an access point, a first indication that afirst wireless station associated with the MLD is in power save mode;and communicate, after transmission of the first indication, with asecond wireless station via a direct link between the second wirelessstation and a third wireless station, the third wireless station beingassociated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

Aspect 74: A multi-link device (MLD), comprising a transceiverconfigured to: transmit, to an access point, an indication to disable alink to a first wireless station associated with the MLD; andcommunicate, after the transmission of the indication, with a secondwireless station via a direct link between the second wireless stationand a third wireless station, the third wireless station beingassociated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

Aspect 75: A first multi-link device (MLD), comprising: a transceiverconfigured to: communicate, with a second MLD, via a dynamic link setcomprising a plurality of links between first access points associatedwith the second MLD and first wireless stations associated with thefirst MLD; transmit, to one or more of the first access points, a firstindication to remove a link in the dynamic link set between the one ormore of the first access points and one or more of the first wirelessstations; and communicate, after the transmission of the firstindication, with a second wireless station via a direct link between thesecond wireless station and a third wireless station associated with thefirst MLD, wherein the direct link is inoperative for the first MLDwhile the one or more of the first wireless stations are communicating.

Aspect 76: A first multi-link device (MLD), comprising: a receiverconfigured to receive, from a second MLD via a first access pointassociated with the first MLD, one or more first frames related toestablishing a direct link between the second MLD and a first wirelessstation, wherein the first wireless station does not support multi-linkoperations; and a processing system configured to relay, to the firstwireless station via the first access point, the one or more firstframes, wherein the one or more first frames include a source addressfield set to an address of a second wireless station associated with thesecond MLD.

Aspect 77: A first wireless station, comprising a transceiver configuredto: transmit, to a second wireless station via an access point, arequest to discover the second wireless station for direct linkcommunications between the first wireless station and the secondwireless station, wherein the request indicates a link forcommunications between the first wireless station and the secondwireless station; and communicate directly with the second wirelessstation via the link indicated in the request.

Aspect 78: A first multi-link device (MLD), comprising: means fortransmitting, to a first wireless station via a direct link between thefirst wireless station and one or more second wireless stationsassociated with the first MLD, a data frame comprising a transmitteraddress field set to an address of the first MLD, which is one of aplurality of addresses associated with the first MLD and the secondwireless stations being associated with the first MLD for multi-linkoperations; and means for communicating with the first wireless stationvia the direct link.

Aspect 79: A multi-link device (MLD), comprising: means forcommunicating with a first wireless station via a direct link betweenthe first wireless station and a second wireless station, the secondwireless station being associated with the MLD, wherein the direct linkis inoperative for the MLD while a third wireless station associatedwith the MLD is communicating; means for receiving, from an accesspoint, a request-to-send (RTS) frame requesting to send data to thethird wireless station associated with the MLD; and means for taking oneor more actions in response to the RTS frame.

Aspect 80: A multi-link device (MLD), comprising: means fortransmitting, to an access point, a first indication that a firstwireless station associated with the MLD is in power save mode; andmeans for communicating, after transmission of the first indication,with a second wireless station via a direct link between the secondwireless station and a third wireless station, the third wirelessstation being associated with the MLD, wherein the direct link isinoperative for the MLD while the first wireless station iscommunicating.

Aspect 81: A multi-link device (MLD), comprising: means fortransmitting, to an access point, an indication to disable a link to afirst wireless station associated with the MLD; and means forcommunicating, after the transmission of the indication, with a secondwireless station via a direct link between the second wireless stationand a third wireless station, the third wireless station beingassociated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

Aspect 82: A first multi-link device (MLD), comprising: means forcommunicating, with a second MLD, via a dynamic link set comprising aplurality of links between first access points associated with thesecond MLD and first wireless stations associated with the first MLD;means for transmitting, to one or more of the first access points, afirst indication to remove a link in the dynamic link set between theone or more of the first access points and one or more of the firstwireless stations; and means for communicating, after the transmissionof the first indication, with a second wireless station via a directlink between the second wireless station and a third wireless stationassociated with the first MLD, wherein the direct link is inoperativefor the first MLD while the one or more of the first wireless stationsare communicating.

Aspect 83: A first multi-link device (MLD), comprising: means forreceiving, from a second MLD via a first access point associated withthe first MLD, one or more first frames related to establishing a directlink between the second MLD and a first wireless station, wherein thefirst wireless station does not support multi-link operations; and meansfor relaying, to the first wireless station via the first access point,the one or more first frames, wherein the one or more first framesinclude a source address field set to an address of a second wirelessstation associated with the second MLD.

Aspect 84: A first wireless station, comprising: means for transmitting,to a second wireless station via an access point, a request to discoverthe second wireless station for direct link communications between thefirst wireless station and the second wireless station, wherein therequest indicates a link for communications between the first wirelessstation and the second wireless station; and means for communicatingdirectly with the second wireless station via the link indicated in therequest.

Aspect 85: An apparatus for wireless communications by a firstmulti-link device (MLD), comprising: an interface configured to output,for transmission to a first wireless station via a direct link betweenthe first wireless station and one or more second wireless stationsassociated with the first MLD, a data frame comprising a transmitteraddress field set to an address of the first MLD, which is one of aplurality of addresses associated with the first MLD and the secondwireless stations being associated with the first MLD for multi-linkoperations; and a processing system configured to communicate with thefirst wireless station via the direct link.

Aspect 86: An apparatus for wireless communications by a multi-linkdevice (MLD), comprising: a processing system configure to communicatewith a first wireless station via a direct link between the firstwireless station and a second wireless station, the second wirelessstation being associated with the MLD, wherein the direct link isinoperative for the MLD while a third wireless station associated withthe MLD is communicating; and an interface configured to obtain, from anaccess point, a request-to-send (RTS) frame requesting to send data tothe third wireless station associated with the MLD, wherein theprocessing system is further configured to take one or more actions inresponse to the RTS frame.

Aspect 87: An apparatus for wireless communications by a multi-linkdevice (MLD), comprising: an interface configured to output, fortransmission to an access point, a first indication that a firstwireless station associated with the MLD is in power save mode; and aprocessing system configured to communicate, after transmission of thefirst indication, with a second wireless station via a direct linkbetween the second wireless station and a third wireless station, thethird wireless station being associated with the MLD, wherein the directlink is inoperative for the MLD while the first wireless station iscommunicating.

Aspect 88: An apparatus for wireless communications by a multi-linkdevice (MLD), comprising: an interface configured to output fortransmission to an access point, an indication to disable a link to afirst wireless station associated with the MLD; and a processing systemconfigured to communicate, after the transmission of the indication,with a second wireless station via a direct link between the secondwireless station and a third wireless station, the third wirelessstation being associated with the MLD, wherein the direct link isinoperative for the MLD while the first wireless station iscommunicating.

Aspect 89: A first multi-link device (MLD), comprising: a processingsystem configured to communicate, with a second MLD, via a dynamic linkset comprising a plurality of links between first access pointsassociated with the second MLD and first wireless stations associatedwith the first MLD; and an interface configured to output, fortransmission to one or more of the first access points, a firstindication to remove a link in the dynamic link set between the one ormore of the first access points and one or more of the first wirelessstations, wherein the processing system is further configured tocommunicate, after the transmission of the first indication, with asecond wireless station via a direct link between the second wirelessstation and a third wireless station associated with the first MLD,wherein the direct link is inoperative for the first MLD while the oneor more of the first wireless stations are communicating.

Aspect 90: A first multi-link device (MLD), comprising: an interfaceconfigured to obtain, from a second MLD via a first access pointassociated with the first MLD, one or more first frames related toestablishing a direct link between the second MLD and a first wirelessstation, wherein the first wireless station does not support multi-linkoperations; and a processing system configured to relay, to the firstwireless station via the first access point, the one or more firstframes, wherein the one or more first frames include a source addressfield set to an address of a second wireless station associated with thesecond MLD.

Aspect 91: A first wireless station, comprising: an interface configuredto output, for transmission to a second wireless station via an accesspoint, a request to discover the second wireless station for direct linkcommunications between the first wireless station and the secondwireless station, wherein the request indicates a link forcommunications between the first wireless station and the secondwireless station; and a processing system configured to communicatedirectly with the second wireless station via the link indicated in therequest.

Aspect 92: A computer-readable medium for wireless communications by afirst multi-link device (MLD), comprising codes executable to: output,for transmission to a first wireless station via a direct link betweenthe first wireless station and one or more second wireless stationsassociated with the first MLD, a data frame comprising a transmitteraddress field set to an address of the first MLD, which is one of aplurality of addresses associated with the first MLD and the secondwireless stations being associated with the first MLD for multi-linkoperations; and communicate with the first wireless station via thedirect link.

Aspect 93: A computer-readable medium for wireless communications by amulti-link device (MLD), comprising codes executable to: communicatewith a first wireless station via a direct link between the firstwireless station and a second wireless station, the second wirelessstation being associated with the MLD, wherein the direct link isinoperative for the MLD while a third wireless station associated withthe MLD is communicating; obtain, from an access point, arequest-to-send (RTS) frame requesting to send data to the thirdwireless station associated with the MLD; and take one or more actionsin response to the RTS frame.

Aspect 94: A computer-readable medium for wireless communications by amulti-link device (MLD), comprising codes executable to: output, fortransmission to an access point, a first indication that a firstwireless station associated with the MLD is in power save mode; andcommunicate, after transmission of the first indication, with a secondwireless station via a direct link between the second wireless stationand a third wireless station, the third wireless station beingassociated with the MLD, wherein the direct link is inoperative for theMLD while the first wireless station is communicating.

Aspect 95: A computer-readable medium for wireless communications by amulti-link device (MLD), comprising codes executable to: output, fortransmission to an access point, an indication to disable a link to afirst wireless station associated with the MLD; and communicate, afterthe transmission of the indication, with a second wireless station via adirect link between the second wireless station and a third wirelessstation, the third wireless station being associated with the MLD,wherein the direct link is inoperative for the MLD while the firstwireless station is communicating.

Aspect 96: A computer-readable medium for wireless communications by afirst multi-link device (MLD), comprising codes executable to:communicate, with a second MLD, via a dynamic link set comprising aplurality of links between first access points associated with thesecond MLD and first wireless stations associated with the first MLD;output, for transmission to one or more of the first access points, afirst indication to remove a link in the dynamic link set between theone or more of the first access points and one or more of the firstwireless stations; and communicate, after the transmission of the firstindication, with a second wireless station via a direct link between thesecond wireless station and a third wireless station associated with thefirst MLD, wherein the direct link is inoperative for the first MLDwhile the one or more of the first wireless stations are communicating.

Aspect 97: A computer-readable medium for wireless communications by afirst multi-link device (MLD), comprising codes executable to: obtain,from a second MLD via a first access point associated with the firstMLD, one or more first frames related to establishing a direct linkbetween the second MLD and a first wireless station, wherein the firstwireless station does not support multi-link operations; and relay, tothe first wireless station via the first access point, the one or morefirst frames, wherein the one or more first frames include a sourceaddress field set to an address of a second wireless station associatedwith the second MLD.

Aspect 98: A computer-readable medium for wireless communications by afirst wireless station, comprising codes executable to: output, fortransmission to a second wireless station via an access point, a requestto discover the second wireless station for direct link communicationsbetween the first wireless station and the second wireless station,wherein the request indicates a link for communications between thefirst wireless station and the second wireless station; and communicatedirectly with the second wireless station via the link indicated in therequest.

Aspect 99: A first multi-link device (MLD), comprising: a memory; and aprocessor coupled to the memory, the processor and the memory beingconfigured to: transmit, to a first wireless station via a direct linkbetween the first wireless station and at least one of a plurality ofsecond wireless stations affiliated with the first MLD, a data framecomprising a transmitter address field set to an address of the firstMLD, which is one of a plurality of addresses associated with the firstMLD and the second wireless stations being affiliated with the first MLDfor multi-link operations, and communicate with the first wirelessstation via the direct link.

Aspect 100: The first MLD of Aspect 99, wherein the address of the firstMLD comprises a multi-link logical medium access control (MAC) address,and the plurality of addresses includes the multi-link logical MACaddress and MAC addresses associated with each of the second wirelessstations.

Aspect 101: The first MLD according to any of Aspects 99 or 100, whereinthe processor and the memory are further configured to transmit, to thefirst wireless station via an access point, a request associated withthe direct link, wherein the request frame comprises a link identifierelement having a direct link initiator address set as the address of thefirst MLD.

Aspect 102: The first MLD according to any of Aspects 99-101, whereinthe processor and the memory are further configured to transmit, to thefirst wireless station, a response associated with the direct link,wherein the response comprises a link identifier element having a directlink responder address set as the address of the first MLD.

Aspect 103: The first MLD according to any of Aspects 99-102, whereinthe processor and the memory are further configured to transmit, to thefirst wireless station, a response associated with the direct linkcomprising the transmitter address field set to the address of the firstMLD.

Aspect 104: The first MLD according to any of Aspects 99-103, whereinthe processor and the memory are further configured to receive, from thefirst wireless station via the direct link, a frame comprising areceiver address field set to the address of the first MLD.

Aspect 105: The first MLD according to any of Aspects 99-104, whereinthe processor and the memory are further configured to: ceasetransmission to the first wireless station via the second wirelessstations, except for the at least one of the second wireless stations,based on the direct link being operative.

Aspect 106: The first MLD according to any of Aspects 99-105, whereinthe processor and the memory are further configured to: generate anencryption key based at least in part on the address of the first MLD;transmit, to the first wireless station, an indication of the encryptionkey; and communicate encrypted frames with the first wireless stationbased on the encryption key.

Aspect 107: The first MLD of Aspect 106, wherein the processor and thememory are further configured to generate the encryption key furtherbased on at least one of an address of an access point MLD or an addressof an access point.

Aspect 108: The first MLD according to any of Aspects 99-107, wherein:the direct link is a tunneled direct link; and the data frame comprisesa MAC header including the transmitter address field.

Aspect 109: The first MLD of Aspect 108, wherein the first wirelessstation is affiliated with a second MLD for multi-link communicationswith the first MLD, and the second MLD further has two or more thirdwireless stations, including the first wireless station, beingaffiliated therewith for multi-link communications with the first MLD.

Aspect 110: The first MLD of Aspect 109, wherein: the direct linkcomprises a plurality of tunneled direct link sessions; and each of theplurality of tunneled direct link sessions is associated with a separatelink between one of the second wireless stations and one of the thirdwireless stations.

Aspect 111: The first MLD of Aspect 109, wherein: the direct linkcomprises a single tunneled direct link session; and a plurality oflinks between the second wireless stations and the third wirelessstations are associated with the single tunneled direct link session.

Aspect 112: The first MLD according to any of Aspects 99-111, whereinthe processor and the memory are further configured to: transmit, to thefirst wireless station, an indication to setup the direct link as amulti-link direct link, wherein the indication comprises at least oneof: a basic service set identifier (BSSID) field comprises a valueindicating to setup the direct link as the multi-link direct link, or amulti-link element in a direct link discovery frame or a direct linksetup frame; and communicate with the first wireless station via one ormore links of the multi-link direct link based on the indication.

Aspect 113: The first MLD of Aspect 112, wherein the value comprises alink identifier associated with the one or more links.

Aspect 114: The first MLD according to any of Aspects 112 or 113,wherein the first wireless station is affiliated with a second MLD formulti-link communications with the first MLD, and the second MLD furtherhas two or more third wireless stations, including the first wirelessstation, being affiliated therewith for multi-link communications withthe first MLD; and wherein the multi-link element includes: a firstindication having an identifier of the direct link in a station profilesub-element associated with the at least one of the second wirelessstations; or a second indication of one or more capabilities of thesecond wireless stations associated with links between the secondwireless stations and the third wireless stations.

Aspect 115: The first MLD according to any of Aspects 99-114, whereinthe processor and the memory are further configured to: receive, fromthe first wireless station via an access point, a request associatedwith the direct link, wherein the request indicates a first link forcommunications between the first wireless station and the at least oneof the second wireless stations, wherein the request indicates the firstlink via a link identifier element having a basic service set identifier(BSSID) field, which includes a value indicating the first link.

Aspect 116: The first MLD according to any of Aspects 99-115, whereinthe processor and the memory are further configured to: transmit, fromthe first wireless station, a plurality of requests associated with thedirect link, wherein each of the requests has a different value for aBSSID field in a link identifier element.

Aspect 117: The first MLD of Aspect 115, wherein a multi-link elementindicates one or more links including the first link in the request.

Aspect 118: The first MLD of Aspect 117, wherein the multi-link elementfurther indicates capability information associated with the first link.

Aspect 119: The first MLD according to any of Aspects 115-118, whereinthe first wireless station is affiliated with a second MLD formulti-link communications with the first MLD, and the second MLD furtherhas two or more third wireless stations, including the first wirelessstation, being affiliated therewith for multi-link communications withthe first MLD; and wherein the processor and the memory are furtherconfigured to: transmit directly, to the first wireless stationaffiliated with the second MLD, a first response responsive to therequest via the first link indicated in the request; transmit directly,to one or more of the third wireless stations affiliated with the secondMLD, a second response responsive to the request via a second link;communicate with the one or more third wireless stations via the secondlink; and communicate with the first wireless station via the first linkindicated in the request.

Aspect 120: The first MLD according to any of Aspects 99-119, wherein:the first wireless station is affiliated with a second MLD formulti-link communications with the first MLD, and the second MLD furtherhas two or more third wireless stations, including the first wirelessstation, being affiliated therewith for multi-link communications withthe first MLD; and the processor and the memory are further configuredto: select at least one link among a plurality of links between thesecond wireless stations affiliated with the first MLD and the thirdwireless stations affiliated with the second MLD, and transmit, to oneor more of the third wireless stations affiliated with the second MLD, arequest to setup the direct link on the selected at least one link.

Aspect 121: The first MLD of Aspect 120, wherein the processor and thememory are further configured to: receive, from the third wirelessstations affiliated with the second MLD, discovery response frames viaone or more of the plurality of links; and wherein the selection of theat least one link is based on a signal quality associated with thediscovery response frames.

Aspect 122: The first MLD according to any of Aspects 120 or 121,wherein the selected at least one link includes two or more of theplurality of links.

Aspect 123: The first MLD according to any of Aspects 99-122, wherein:the first wireless station is affiliated with a second MLD formulti-link communications with the first MLD, and the second MLD furtherhas two or more third wireless stations, including the first wirelessstation, being affiliated therewith for multi-link communications withthe first MLD; and the processor and the memory are further configuredto: transmit, to one of the third wireless stations affiliated with thesecond MLD via an access point, a first request to discover a peerwireless station for the direct link, wherein the first requestindicates a first link for communications between the one of the thirdwireless stations and one of the second wireless stations affiliatedwith the first MLD, determine that a duration has passed withoutreceiving a response to the first request, and transmit, to another oneof the third wireless stations affiliated with the second MLD via theaccess point, a second request to discover a peer wireless station forthe direct link based on the determination, wherein the second requestindicates a second link for communications between the other one of thethird wireless stations and another one of the second wireless stationsaffiliated with the first MLD.

Aspect 124: A method of wireless communication by a first multi-linkdevice (MLD), comprising: transmitting, to a first wireless station viaa direct link between the first wireless station and at least one of aplurality of second wireless stations affiliated with the first MLD, adata frame comprising a transmitter address field set to an address ofthe first MLD, which is one of a plurality of addresses associated withthe first MLD and the second wireless stations being affiliated with thefirst MLD for multi-link operations, and communicating with the firstwireless station via the direct link.

Aspect 125: The method of Aspect 124, wherein the address of the firstMLD comprises a multi-link logical medium access control (MAC) address,and the plurality of addresses includes the multi-link logical MACaddress and MAC addresses associated with each of the second wirelessstations.

Aspect 126: The method according to any of Aspects 124 or 125, furthercomprising transmitting, to the first wireless station via an accesspoint, a request associated with the direct link, wherein the requestframe comprises a link identifier element having a direct link initiatoraddress set as the address of the first MLD.

Aspect 127: The method according to any of Aspects 124-126, furthercomprising transmitting, to the first wireless station, a responseassociated with the direct link, wherein the response comprises a linkidentifier element having a direct link responder address set as theaddress of the first MLD.

Aspect 128: The method according to any of Aspects 124-127, furthercomprising ceasing transmission to the first wireless station via thesecond wireless stations, except for the at least one of the secondwireless stations, based on the direct link being operative.

Aspect 129: A multi-link device (MLD), comprising: a memory; and aprocessor coupled to the memory, the processor and the memory beingconfigured to: establish a direct link between a first wireless stationand a second wireless station affiliated with the MLD; and communicatewith the first wireless station via the direct link, wherein the directlink is inoperative for the MLD while a third wireless stationaffiliated with the MLD is communicating.

Aspect 130: The MLD of Aspect 129, wherein the processor and the memoryare further configured to transmit to an access point (AP) MLD withwhich the MLD has performed association, an indication of a stateassociated with the MLD or one or more wireless stations affiliated withthe MLD.

Aspect 131: The MLD according to any of Aspects 129 or 130, wherein thethird wireless station is inoperative while the direct link iscommunicating.

Aspect 132: The MLD according to any of Aspects 129-131, wherein theprocessor and the memory are further configured to: receive, from anaccess point affiliated with an AP MLD, a first frame requesting to senddata to the third wireless station affiliated with the MLD in responseto the indication of the state; and take one or more actions in responseto the first frame.

Aspect 133: The MLD according to any of Aspects 129-132, wherein theprocessor and the memory are further configured to: transmit, to theaccess point affiliated with the AP MLD, a second frame indicating theaccess point affiliated with an AP MLD is free to transmit data to theMLD; and receive, from the access point affiliated with an AP MLD, datavia the third wireless station based on the transmission of the secondframe.

Aspect 134: The MLD according to any of Aspects 132 or 133, wherein theprocessor and the memory are further configured to: receive the firstframe via the third wireless station on a channel in which the accesspoint affiliated with the AP MLD is communicating with the thirdwireless station; and transmit the second from via the third wirelessstation on the channel.

Aspect 135: The MLD according to any of Aspects 132-134, wherein theprocessor and the memory are further configured to ignore the firstframe if the second wireless station is communicating with the firstwireless station.

Aspect 136: The MLD according to any of Aspects 132-135, wherein thestate indicates to enable transmission of the first frame before atransmission from the AP MLD to the third wireless affiliated with theMLD.

Aspect 137: The MLD according to any of Aspects 132-136, wherein theprocessor and the memory are further configured to transmit, to theaccess point or the AP MLD, an update to the state indicating to disabletransmission of the first frame before a transmission from the AP MLD tothe third wireless station affiliated with the MLD.

Aspect 138: The MLD according to any of Aspects 129-137, wherein theindication is transmitted via a control field of a medium access control(MAC) header of a frame, a management frame, or a control frame.

Aspect 139: An access point, comprising: a memory; and a processorcoupled to the memory, the processor and the memory are furtherconfigured to: receive, from a multi-link device (MLD), an indication ofa state associated with the MLD or one or more wireless stationsaffiliated with the MLD, transmit, to the MLD, a first frame requestingto send data to the one or more wireless stations affiliated with theMLD based on the state, and transmit, to the one or more wirelessstations, the data if a second frame granting permission to send thedata is received by the access point from the MLD.

Aspect 140: The access point of Aspect 139, wherein the MLD hasperformed association with an access point (AP) MLD with which theaccess point is affiliated, and the state indicates to enabletransmission of the first frame before a transmission from the AP MLD tothe one or more wireless stations affiliated with the MLD.

Aspect 141: The access point according to any of Aspects 139 or 140,wherein the MLD has performed association with an AP MLD with which theaccess point is affiliated, and wherein the processor and the memory arefurther configured to receive, from the MLD, an update to the stateindicating to disable transmission of the first frame before atransmission from the AP MLD to the one or more wireless stationsaffiliated with the MLD.

Aspect 142: The access point of Aspect 141, wherein the processor andthe memory are further configured to: transmit the first frame to theone or more wireless stations on a channel in which the access pointaffiliated with the AP MLD is communicating with the one or morewireless stations; and receive the second from the one or more wirelessstations on the channel.

Aspect 143: The access point according to any of Aspects 139-142,wherein the indication is received via a control field of a mediumaccess control (MAC) header of a frame, a management frame, or a controlframe.

Aspect 144: A multi-link device (MLD), comprising: a memory; and aprocessor coupled to the memory, the processor and the memory beingconfigured to: transmit, to an access point or an access point (AP) MLD,a first indication associated with a first wireless station affiliatedwith the MLD, and communicate, after transmission of the firstindication, with a second wireless station via a direct link between thesecond wireless station and a third wireless station, the third wirelessstation being affiliated with the MLD, wherein the direct link isinoperative for the MLD while the first wireless station iscommunicating.

Aspect 145: The MLD of Aspect 144, wherein the processor and the memoryare further configured to: transmit, to the access point or the AP MLD,a second indication that the first wireless station is in active modeafter ending the communication with the second wireless station.

Aspect 146: The MLD of Aspect 145, wherein the processor and the memoryare further configured to: communicate, with the access point, via thefirst wireless station after the transmission of the second indication.

Aspect 147: The MLD according to any of Aspects 144-146, wherein:

the communication with the second wireless station via the thirdwireless station occurs when the first wireless station is notcommunicating; or the communication with the access point via the firstwireless station occurs when the third wireless station is notcommunicating.

Aspect 148: The MLD according to any of Aspects 144-147, wherein thefirst indication includes at least one of: an indication that the firstwireless station is in power save mode; an indication to disable a firstlink to the first wireless station; or an indication to remove a secondlink in a dynamic link set to the first wireless station.

Aspect 149: The MLD according to any of Aspects 144-148, wherein thefirst indication is transmitted via a control field of a medium accesscontrol (MAC) header of a frame, a management frame, or a control frame.

Aspect 150: A method of wireless communication by a multi-link device(MLD), comprising: establishing a direct link between a first wirelessstation and a second wireless station affiliated with the MLD; andcommunicating with the first wireless station via the direct link,wherein the direct link is inoperative for the MLD while a thirdwireless station affiliated with the MLD is communicating.

Aspect 151: The method of Aspect 150, further comprising transmitting,to an access point (AP) MLD with which the MLD has performed anassociation, an indication of a state associated with the MLD or one ormore wireless stations affiliated with the MLD.

Aspect 152: The method of Aspect 151, wherein the third wireless stationis inoperative while the direct link is communicating.

Aspect 153: The method according to any of Aspects 151 or 152, furthercomprising: receiving, from an access point affiliated with the AP MLD,a first frame requesting to send data to the third wireless stationaffiliated with the MLD in response to the indication of the state; andtaking one or more actions in response to the first frame.

Aspect 154: The method of Aspect 153, further comprising: transmitting,to the access point affiliated with the MLD, a second frame indicatingthe access point is free to transmit data to the MLD; and receiving,from the access point affiliated with the MLD, data via the thirdwireless station based on the transmission of the second frame.

Aspect 155: The method of Aspect 154, further comprising: receiving thefirst frame via the third wireless station on a channel in which theaccess point affiliated with the AP MLD is communicating with the thirdwireless station; and transmitting the second from via the thirdwireless station on the channel.

Aspect 156: The method according to any of Aspects 154-155, furthercomprising ignoring the first frame if the second wireless station iscommunicating with the first wireless station.

Aspect 157: The method according to any of Aspects 154-156, wherein thestate indicates to enable transmission of the first frame before atransmission from the AP MLD to the third wireless station affiliatedwith the MLD.

Aspect 158: The method according to any of Aspects 154-157, furthercomprising transmitting, to the access point or the AP MLD, an update tothe state indicating to disable transmission of the first frame before atransmission from the AP MLD to the third wireless station affiliatedwith the MLD.

Aspect 159: An apparatus, comprising: a memory comprising executableinstructions; one or more processors configured to execute theexecutable instructions and cause the apparatus to perform a method inaccordance with any of Aspects 1-70, 124-128, or 150-158.

Aspect 160: An apparatus, comprising means for performing a method inaccordance with any of Aspects 1-70, 124-128, or 150-158.

Aspect 161: A computer-readable medium comprising executableinstructions that, when executed by one or more processors of anapparatus, cause the apparatus to perform a method in accordance withany of Aspects 1-70, 124-128, or 150-158.

Aspect 162: A computer program product embodied on a computer-readablestorage medium comprising code for performing a method in accordancewith any of Aspects 1-70, 124-128, or 150-158.

Techniques described herein provide various advantages to direct linkcommunications in multi-link applications. For example, the varioustechniques for handling TDLS with MLO may enable an MLD to setup a TDLSsession with a legacy STA or another MLD, which may provide desirablelatencies and/or throughputs between the TDLS peer STAs.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for” or, in the case of a method claim, theelement is recited using the phrase “step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components.

Means for receiving may include a transceiver, a receiver or at leastone antenna and at least one receive processor illustrated in FIG. 2.Means for transmitting, means for sending or means for outputting mayinclude, a transceiver, a transmitter or at least one antenna and atleast one transmit processor illustrated in FIG. 2. Means forcommunicating, means for generating, means for taking one or moreactions, means for selecting, means for determining, means for ignoring,means for mapping and means for relaying may include a processingsystem, which may include one or more processors, such as processors 260m, 270 m, 288 m, and/or 290 m of the STA 120 m and/or processors 210,220, 240, and/or 242 of the AP 110 shown in FIG. 2.

In some cases, rather than actually transmitting a frame a device mayhave an interface to output a frame for transmission (a means foroutputting). For example, a processor may output a frame, via a businterface, to a radio frequency (RF) front end for transmission.Similarly, rather than actually receiving a frame, a device may have aninterface to obtain a frame received from another device (a means forobtaining). For example, a processor may obtain (or receive) a frame,via a bus interface, from an RF front end for reception.

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as combinations that include multiplesof one or more members (aa, aabb, aabbcc, bb, bbcc, and/or cc).

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thepresent disclosure may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in any form of storage medium that is knownin the art. Some examples of storage media that may be used includerandom access memory (RAM), read only memory (ROM), flash memory, EPROMmemory, EEPROM memory, registers, a hard disk, a removable disk, aCD-ROM and so forth. A software module may comprise a singleinstruction, or many instructions, and may be distributed over severaldifferent code segments, among different programs, and across multiplestorage media. A storage medium may be coupled to a processor such thatthe processor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

The functions described may be implemented in hardware, software,firmware, or any combination thereof. If implemented in hardware, anexample hardware configuration may comprise a processing system in awireless node. The processing system may be implemented with a busarchitecture. The bus may include any number of interconnecting busesand bridges depending on the specific application of the processingsystem and the overall design constraints. The bus may link togethervarious circuits including a processor, machine-readable media, and abus interface. The bus interface may be used to connect a networkadapter, among other things, to the processing system via the bus. Thenetwork adapter may be used to implement the signal processing functionsof the PHY layer. In the case of a wireless station 120 (see FIG. 1), auser interface (e.g., keypad, display, mouse, joystick, etc.) may alsobe connected to the bus. The bus may also link various other circuitssuch as timing sources, peripherals, voltage regulators, powermanagement circuits, and the like, which are well known in the art, andtherefore, will not be described any further.

The processor may be responsible for managing the bus and generalprocessing, including the execution of software stored on themachine-readable media. The processor may be implemented with one ormore general-purpose and/or special-purpose processors. Examples includemicroprocessors, microcontrollers, DSP processors, and other circuitrythat can execute software. Software shall be construed broadly to meaninstructions, data, or any combination thereof, whether referred to assoftware, firmware, middleware, microcode, hardware descriptionlanguage, or otherwise. Machine-readable media may include, by way ofexample, RAM (Random Access Memory), flash memory, ROM (Read OnlyMemory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product. The computer-program product may comprisepackaging materials.

In a hardware implementation, the machine-readable media may be part ofthe processing system separate from the processor. However, as thoseskilled in the art will readily appreciate, the machine-readable media,or any portion thereof, may be external to the processing system. By wayof example, the machine-readable media may include a transmission line,a carrier wave modulated by data, and/or a computer product separatefrom the wireless node, all which may be accessed by the processorthrough the bus interface. Alternatively, or in addition, themachine-readable media, or any portion thereof, may be integrated intothe processor, such as the case may be with cache and/or generalregister files.

The processing system may be configured as a general-purpose processingsystem with one or more microprocessors providing the processorfunctionality and external memory providing at least a portion of themachine-readable media, all linked together with other supportingcircuitry through an external bus architecture. Alternatively, theprocessing system may be implemented with an ASIC (Application SpecificIntegrated Circuit) with the processor, the bus interface, the userinterface in the case of an access terminal), supporting circuitry, andat least a portion of the machine-readable media integrated into asingle chip, or with one or more FPGAs (Field Programmable Gate Arrays),PLDs (Programmable Logic Devices), controllers, state machines, gatedlogic, discrete hardware components, or any other suitable circuitry, orany combination of circuits that can perform the various functionalitydescribed throughout this disclosure. Those skilled in the art willrecognize how best to implement the described functionality for theprocessing system depending on the particular application and theoverall design constraints imposed on the overall system.

The machine-readable media may comprise a number of software modules.The software modules include instructions that, when executed by theprocessor, cause the processing system to perform various functions. Thesoftware modules may include a transmission module and a receivingmodule. Each software module may reside in a single storage device or bedistributed across multiple storage devices. By way of example, asoftware module may be loaded into RAM from a hard drive when atriggering event occurs. During execution of the software module, theprocessor may load some of the instructions into cache to increaseaccess speed. One or more cache lines may then be loaded into a generalregister file for execution by the processor. When referring to thefunctionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer-readable medium.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a computer. By way of example,and not limitation, such computer-readable media can comprise RAM, ROM,EEPROM, CD-ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other medium that can be used tocarry or store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared (IR),radio, and microwave, then the coaxial cable, fiber optic cable, twistedpair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For certain aspects, the computer program product may includepackaging material.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a wireless station and/or accesspoint as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a wirelessstation and/or access point can obtain the various methods upon couplingor providing the storage means to the device. Moreover, any othersuitable technique for providing the methods and techniques describedherein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

1. A first multi-link device (MLD), comprising: a memory; and aprocessor coupled to the memory, the processor and the memory beingconfigured to: transmit, to a first wireless station via a direct linkbetween the first wireless station and at least one of a plurality ofsecond wireless stations affiliated with the first MLD, a data framecomprising a transmitter address field set to an address of the firstMLD, which is one of a plurality of addresses associated with the firstMLD and the second wireless stations being affiliated with the first MLDfor multi-link operations, and communicate with the first wirelessstation via the direct link.
 2. The first MLD of claim 1, wherein theaddress of the first MLD comprises a multi-link logical medium accesscontrol (MAC) address, and the plurality of addresses includes themulti-link logical MAC address and MAC addresses associated with each ofthe second wireless stations.
 3. The first MLD of claim 1, wherein theprocessor and the memory are further configured to transmit, to thefirst wireless station via an access point, a request associated withthe direct link, wherein the request frame comprises a link identifierelement having a direct link initiator address set as the address of thefirst MLD.
 4. The first MLD of claim 1, wherein the processor and thememory are further configured to transmit, to the first wirelessstation, a response associated with the direct link, wherein theresponse comprises a link identifier element having a direct linkresponder address set as the address of the first MLD.
 5. The first MLDof claim 1, wherein the processor and the memory are further configuredto transmit, to the first wireless station, a response associated withthe direct link comprising the transmitter address field set to theaddress of the first MLD.
 6. The first MLD of claim 1, wherein theprocessor and the memory are further configured to receive, from thefirst wireless station via the direct link, a frame comprising areceiver address field set to the address of the first MLD.
 7. The firstMLD of claim 1, wherein the processor and the memory are furtherconfigured to: cease transmission to the first wireless station via thesecond wireless stations, except for the at least one of the secondwireless stations, based on the direct link being operative.
 8. Thefirst MLD of claim 1, wherein the processor and the memory are furtherconfigured to: generate an encryption key based at least in part on theaddress of the first MLD; transmit, to the first wireless station, anindication of the encryption key; and communicate encrypted frames withthe first wireless station based on the encryption key.
 9. The first MLDof claim 8, wherein the processor and the memory are further configuredto generate the encryption key further based on at least one of anaddress of an access point MLD or an address of an access point.
 10. Thefirst MLD of claim 1, wherein: the direct link is a tunneled directlink; and the data frame comprises a MAC header including thetransmitter address field.
 11. The first MLD of claim 10, wherein thefirst wireless station is affiliated with a second MLD for multi-linkcommunications with the first MLD, and the second MLD further has two ormore third wireless stations, including the first wireless station,being affiliated therewith for multi-link communications with the firstMLD.
 12. The first MLD of claim 11, wherein: the direct link comprises aplurality of tunneled direct link sessions; and each of the plurality oftunneled direct link sessions is associated with a separate link betweenone of the second wireless stations and one of the third wirelessstations.
 13. The first MLD of claim 11, wherein: the direct linkcomprises a single tunneled direct link session; and a plurality oflinks between the second wireless stations and the third wirelessstations are associated with the single tunneled direct link session.14. The first MLD of claim 1, wherein the processor and the memory arefurther configured to: transmit, to the first wireless station, anindication to setup the direct link as a multi-link direct link, whereinthe indication comprises at least one of: a basic service set identifier(BSSID) field comprises a value indicating to setup the direct link asthe multi-link direct link, or a multi-link element in a direct linkdiscovery frame or a direct link setup frame; and communicate with thefirst wireless station via one or more links of the multi-link directlink based on the indication.
 15. The first MLD of claim 14, wherein thevalue comprises a link identifier associated with the one or more links.16. The first MLD of claim 14, wherein: the first wireless station isaffiliated with a second MLD for multi-link communications with thefirst MLD, and the second MLD further has two or more third wirelessstations, including the first wireless station, being affiliatedtherewith for multi-link communications with the first MLD; and themulti-link element includes: a first indication having an identifier ofthe direct link in a station profile sub-element associated with the atleast one of the second wireless stations; or a second indication of oneor more capabilities of the second wireless stations associated withlinks between the second wireless stations and the third wirelessstations.
 17. The first MLD of claim 1, wherein the processor and thememory are further configured to: receive, from the first wirelessstation via an access point, a request associated with the direct link,wherein the request indicates a first link for communications betweenthe first wireless station and the at least one of the second wirelessstations, wherein the request indicates the first link via a linkidentifier element having a basic service set identifier (BSSID) field,which includes a value indicating the first link.
 18. The first MLD ofclaim 1, wherein the processor and the memory are further configured to:transmit, from the first wireless station, a plurality of requestsassociated with the direct link, wherein each of the requests has adifferent value for a BSSID field in a link identifier element.
 19. Thefirst MLD of claim 17, wherein a multi-link element indicates one ormore links including the first link in the request.
 20. The first MLD ofclaim 19, wherein the multi-link element further indicates capabilityinformation associated with the first link.
 21. The first MLD of claim17, wherein: the first wireless station is affiliated with a second MLDfor multi-link communications with the first MLD, and the second MLDfurther has two or more third wireless stations, including the firstwireless station, being affiliated therewith for multi-linkcommunications with the first MLD; and the processor and the memory arefurther configured to: transmit directly, to the first wireless stationaffiliated with the second MLD, a first response responsive to therequest via the first link indicated in the request; transmit directly,to one or more of the third wireless stations affiliated with the secondMLD, a second response responsive to the request via a second link;communicate with the one or more third wireless stations via the secondlink; and communicate with the first wireless station via the first linkindicated in the request.
 22. The first MLD of claim 1, wherein: thefirst wireless station is affiliated with a second MLD for multi-linkcommunications with the first MLD, and the second MLD further has two ormore third wireless stations, including the first wireless station,being affiliated therewith for multi-link communications with the firstMLD; and the processor and the memory are further configured to: selectat least one link among a plurality of links between the second wirelessstations affiliated with the first MLD and the third wireless stationsaffiliated with the second MLD, and transmit, to one or more of thethird wireless stations affiliated with the second MLD, a request tosetup the direct link on the selected at least one link.
 23. The firstMLD of claim 22, wherein the processor and the memory are furtherconfigured to: receive, from the third wireless stations affiliated withthe second MLD, discovery response frames via one or more of theplurality of links; and wherein the selection of the at least one linkis based on a signal quality associated with the discovery responseframes.
 24. The first MLD of claim 22, wherein the selected at least onelink includes two or more of the plurality of links.
 25. The first MLDof claim 1, wherein: the first wireless station is affiliated with asecond MLD for multi-link communications with the first MLD, and thesecond MLD further has two or more third wireless stations, includingthe first wireless station, being affiliated therewith for multi-linkcommunications with the first MLD; and the processor and the memory arefurther configured to: transmit, to one of the third wireless stationsaffiliated with the second MLD via an access point, a first request todiscover a peer wireless station for the direct link, wherein the firstrequest indicates a first link for communications between the one of thethird wireless stations and one of the second wireless stationsaffiliated with the first MLD, determine that a duration has passedwithout receiving a response to the first request, and transmit, toanother one of the third wireless stations affiliated with the secondMLD via the access point, a second request to discover a peer wirelessstation for the direct link based on the determination, wherein thesecond request indicates a second link for communications between theother one of the third wireless stations and another one of the secondwireless stations affiliated with the first MLD.
 26. A method ofwireless communication by a first multi-link device (MLD), comprising:transmitting, to a first wireless station via a direct link between thefirst wireless station and at least one of a plurality of secondwireless stations affiliated with the first MLD, a data frame comprisinga transmitter address field set to an address of the first MLD, which isone of a plurality of addresses associated with the first MLD and thesecond wireless stations being affiliated with the first MLD formulti-link operations, and communicating with the first wireless stationvia the direct link.
 27. The method of claim 26, wherein the address ofthe first MLD comprises a multi-link logical medium access control (MAC)address, and the plurality of addresses includes the multi-link logicalMAC address and MAC addresses associated with each of the secondwireless stations.
 28. The method of claim 26, further comprisingtransmitting, to the first wireless station via an access point, arequest associated with the direct link, wherein the request framecomprises a link identifier element having a direct link initiatoraddress set as the address of the first MLD.
 29. The method of claim 26,further comprising transmitting, to the first wireless station, aresponse associated with the direct link, wherein the response comprisesa link identifier element having a direct link responder address set asthe address of the first MLD.
 30. The method of claim 26, furthercomprising ceasing transmission to the first wireless station via thesecond wireless stations, except for the at least one of the secondwireless stations, based on the direct link being operative.